81568502540 has 24 divisors (see below), whose sum is σ = 195764406432. Its totient is φ = 27966343680.

The previous prime is 81568502489. The next prime is 81568502573. The reversal of 81568502540 is 4520586518.

It is a junction number, because it is equal to n+sod(n) for n = 81568502491 and 81568502500.

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, 291315941 + ... + 291316220.

It is an arithmetic number, because the mean of its divisors is an integer number (8156850268).

Almost surely, 2^81568502540 is an apocalyptic number.

It is an amenable number.

81568502540 is an abundant number, since it is smaller than the sum of its proper divisors (114195903892).

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

81568502540 is a wasteful number, since it uses less digits than its factorization.

81568502540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 582632177 (or 582632175 counting only the distinct ones).

The product of its (nonzero) digits is 384000, while the sum is 44.

The spelling of 81568502540 in words is "eighty-one billion, five hundred sixty-eight million, five hundred two thousand, five hundred forty".