161431556620 has 12 divisors (see below), whose sum is σ = 339006268944. Its totient is φ = 64572622640.

The previous prime is 161431556581. The next prime is 161431556647. The reversal of 161431556620 is 26655134161.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4035788896 + ... + 4035788935.

It is an arithmetic number, because the mean of its divisors is an integer number (28250522412).

Almost surely, 2^161431556620 is an apocalyptic number.

161431556620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161431556620 is an abundant number, since it is smaller than the sum of its proper divisors (177574712324).

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

161431556620 is a wasteful number, since it uses less digits than its factorization.

161431556620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8071577840 (or 8071577838 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 40.

The spelling of 161431556620 in words is "one hundred sixty-one billion, four hundred thirty-one million, five hundred fifty-six thousand, six hundred twenty".