81059640 has 64 divisors (see below), whose sum is σ = 251575200. Its totient is φ = 20869632.

The previous prime is 81059639. The next prime is 81059651. The reversal of 81059640 is 4695018.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8167 + ... + 15126.

Almost surely, 2^81059640 is an apocalyptic number.

It is an amenable number.

81059640 is an abundant number, since it is smaller than the sum of its proper divisors (170515560).

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

81059640 is a wasteful number, since it uses less digits than its factorization.

81059640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23336 (or 23332 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 33.

The square root of 81059640 is about 9003.3127236590. The cubic root of 81059640 is about 432.7810373416.

The spelling of 81059640 in words is "eighty-one million, fifty-nine thousand, six hundred forty".