161311388556 has 48 divisors (see below), whose sum is σ = 381919646304. Its totient is φ = 52986479616.

The previous prime is 161311388533. The next prime is 161311388591. The reversal of 161311388556 is 655883113161.

161311388556 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 109231 + ... + 578406.

It is an arithmetic number, because the mean of its divisors is an integer number (7956659298).

Almost surely, 2^161311388556 is an apocalyptic number.

It is an amenable number.

161311388556 is an abundant number, since it is smaller than the sum of its proper divisors (220608257748).

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

161311388556 is a wasteful number, since it uses less digits than its factorization.

161311388556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 687930 (or 687928 counting only the distinct ones).

The product of its digits is 518400, while the sum is 48.

The spelling of 161311388556 in words is "one hundred sixty-one billion, three hundred eleven million, three hundred eighty-eight thousand, five hundred fifty-six".