81532656 has 100 divisors (see below), whose sum is σ = 240634152. Its totient is φ = 26642304.

The previous prime is 81532621. The next prime is 81532669. The reversal of 81532656 is 65623518.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 81532656.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 68095 + ... + 69281.

Almost surely, 2^81532656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81532656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120317076).

81532656 is an abundant number, since it is smaller than the sum of its proper divisors (159101496).

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

81532656 is a wasteful number, since it uses less digits than its factorization.

81532656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1260 (or 1245 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 81532656 is about 9029.5435100563. The cubic root of 81532656 is about 433.6212230277.

The spelling of 81532656 in words is "eighty-one million, five hundred thirty-two thousand, six hundred fifty-six".