81438576 has 40 divisors (see below), whose sum is σ = 210767760. Its totient is φ = 27096576.

The previous prime is 81438563. The next prime is 81438593. The reversal of 81438576 is 67583418.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32836 + ... + 35228.

It is an arithmetic number, because the mean of its divisors is an integer number (5269194).

Almost surely, 2^81438576 is an apocalyptic number.

It is an amenable number.

81438576 is an abundant number, since it is smaller than the sum of its proper divisors (129329184).

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

81438576 is a wasteful number, since it uses less digits than its factorization.

81438576 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3113 (or 3107 counting only the distinct ones).

The product of its digits is 161280, while the sum is 42.

The square root of 81438576 is about 9024.3324406850. The cubic root of 81438576 is about 433.4543746024.

The spelling of 81438576 in words is "eighty-one million, four hundred thirty-eight thousand, five hundred seventy-six".