81001056 has 48 divisors (see below), whose sum is σ = 225139824. Its totient is φ = 25411584.

The previous prime is 81001043. The next prime is 81001097. The reversal of 81001056 is 65010018.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×81001056² = 13122342146230272, which contains 22 as substring.

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, 23185 + ... + 26448.

It is an arithmetic number, because the mean of its divisors is an integer number (4690413).

Almost surely, 2^81001056 is an apocalyptic number.

It is an amenable number.

81001056 is an abundant number, since it is smaller than the sum of its proper divisors (144138768).

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

81001056 is a wasteful number, since it uses less digits than its factorization.

81001056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49663 (or 49655 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 21.

The square root of 81001056 is about 9000.0586664755. The cubic root of 81001056 is about 432.6767513502.

The spelling of 81001056 in words is "eighty-one million, one thousand, fifty-six".