85815656640 has 168 divisors, whose sum is σ = 337337339040. Its totient is φ = 19615002624.

The previous prime is 85815656621. The next prime is 85815656669. The reversal of 85815656640 is 4665651858.

85815656640 is a `hidden beast` number, since 8 + 581 + 5 + 6 + 56 + 6 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (168).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2108205 + ... + 2148524.

Almost surely, 2^85815656640 is an apocalyptic number.

85815656640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

85815656640 is an abundant number, since it is smaller than the sum of its proper divisors (251521682400).

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

85815656640 is a wasteful number, since it uses less digits than its factorization.

85815656640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4256759 (or 4256746 counting only the distinct ones).

The product of its (nonzero) digits is 6912000, while the sum is 54.

The spelling of 85815656640 in words is "eighty-five billion, eight hundred fifteen million, six hundred fifty-six thousand, six hundred forty".