81532368 has 60 divisors (see below), whose sum is σ = 229290880. Its totient is φ = 27044928.

The previous prime is 81532307. The next prime is 81532379. The reversal of 81532368 is 86323518.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 30843 + ... + 33381.

Almost surely, 2^81532368 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 81532368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114645440).

81532368 is an abundant number, since it is smaller than the sum of its proper divisors (147758512).

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

81532368 is a wasteful number, since it uses less digits than its factorization.

81532368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2776 (or 2767 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 81532368 is about 9029.5275623922. The cubic root of 81532368 is about 433.6207124631.

The spelling of 81532368 in words is "eighty-one million, five hundred thirty-two thousand, three hundred sixty-eight".