81983760 has 80 divisors (see below), whose sum is σ = 256483584. Its totient is φ = 21661696.

The previous prime is 81983711. The next prime is 81983761. The reversal of 81983760 is 6738918.

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 (81983761) 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, 25609 + ... + 28631.

Almost surely, 2^81983760 is an apocalyptic number.

81983760 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 81983760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128241792).

81983760 is an abundant number, since it is smaller than the sum of its proper divisors (174499824).

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

81983760 is a wasteful number, since it uses less digits than its factorization.

81983760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3152 (or 3146 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 42.

The square root of 81983760 is about 9054.4883897435. The cubic root of 81983760 is about 434.4194660413.

The spelling of 81983760 in words is "eighty-one million, nine hundred eighty-three thousand, seven hundred sixty".