161865856064 has 56 divisors (see below), whose sum is σ = 356147193216. Its totient is φ = 72369216000.

The previous prime is 161865856051. The next prime is 161865856157. The reversal of 161865856064 is 460658568161.

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, 1841672 + ... + 1927559.

Almost surely, 2^161865856064 is an apocalyptic number.

It is an amenable number.

161865856064 is an abundant number, since it is smaller than the sum of its proper divisors (194281337152).

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

161865856064 is a wasteful number, since it uses less digits than its factorization.

161865856064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3769315 (or 3769305 counting only the distinct ones).

The product of its (nonzero) digits is 8294400, while the sum is 56.

The spelling of 161865856064 in words is "one hundred sixty-one billion, eight hundred sixty-five million, eight hundred fifty-six thousand, sixty-four".