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81230480 = 24523131337
BaseRepresentation
bin1001101011101…
…11101010010000
312122211221021022
410311313222100
5131243333410
612021015012
72004306362
oct465675220
9178757238
1081230480
1141941731
1223254468
1313aa1496
14ab06d32
1571e8455
hex4d77a90

81230480 has 80 divisors (see below), whose sum is σ = 199165824. Its totient is φ = 30750720.

The previous prime is 81230477. The next prime is 81230489. The reversal of 81230480 is 8403218.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (81230489) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 240872 + ... + 241208.

Almost surely, 281230480 is an apocalyptic number.

81230480 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81230480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99582912).

81230480 is an abundant number, since it is smaller than the sum of its proper divisors (117935344).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81230480 is a wasteful number, since it uses less digits than its factorization.

81230480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 504 (or 498 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 81230480 is about 9012.7953488360. The cubic root of 81230480 is about 433.0848647902.

Adding to 81230480 its reverse (8403218), we get a palindrome (89633698).

The spelling of 81230480 in words is "eighty-one million, two hundred thirty thousand, four hundred eighty".

Divisors: 1 2 4 5 8 10 16 20 23 40 46 80 92 115 131 184 230 262 337 368 460 524 655 674 920 1048 1310 1348 1685 1840 2096 2620 2696 3013 3370 5240 5392 6026 6740 7751 10480 12052 13480 15065 15502 24104 26960 30130 31004 38755 44147 48208 60260 62008 77510 88294 120520 124016 155020 176588 220735 241040 310040 353176 441470 620080 706352 882940 1015381 1765880 2030762 3531760 4061524 5076905 8123048 10153810 16246096 20307620 40615240 81230480