81040056 has 16 divisors (see below), whose sum is σ = 202600200. Its totient is φ = 27013344.

The previous prime is 81040049. The next prime is 81040081. The reversal of 81040056 is 65004018.

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 3376669 = 81040056 / (8 + 1 + 0 + 4 + 0 + 0 + 5 + 6).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1688311 + ... + 1688358.

Almost surely, 2^81040056 is an apocalyptic number.

It is an amenable number.

81040056 is an abundant number, since it is smaller than the sum of its proper divisors (121560144).

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

81040056 is a wasteful number, since it uses less digits than its factorization.

81040056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3376678 (or 3376674 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 81040056 is about 9002.2250582842. The cubic root of 81040056 is about 432.7461812509.

The spelling of 81040056 in words is "eighty-one million, forty thousand, fifty-six".