81264330 has 256 divisors, whose sum is σ = 272793600. Its totient is φ = 16796160.

The previous prime is 81264319. The next prime is 81264331. The reversal of 81264330 is 3346218.

It is a happy number.

81264330 is a `hidden beast` number, since 8 + 12 + 643 + 3 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 81264294 and 81264303.

It is not an unprimeable number, because it can be changed into a prime (81264331) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1113174 + ... + 1113246.

It is an arithmetic number, because the mean of its divisors is an integer number (1065600).

Almost surely, 2^81264330 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81264330, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136396800).

81264330 is an abundant number, since it is smaller than the sum of its proper divisors (191529270).

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

81264330 is a wasteful number, since it uses less digits than its factorization.

81264330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146 (or 140 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 81264330 is about 9014.6730389959. The cubic root of 81264330 is about 433.1450141611.

The spelling of 81264330 in words is "eighty-one million, two hundred sixty-four thousand, three hundred thirty".