161566505065656 has 96 divisors (see below), whose sum is σ = 448261608085200. Its totient is φ = 52540420538880.

The previous prime is 161566505065601. The next prime is 161566505065663. The reversal of 161566505065656 is 656560505665161.

161566505065656 is a `hidden beast` number, since 1 + 6 + 1 + 5 + 6 + 6 + 505 + 0 + 65 + 65 + 6 = 666.

It is a super-2 number, since 2×161566505065656² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 161566505065593 and 161566505065602.

It is a congruent number.

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, 102713610 + ... + 104274726.

Almost surely, 2^{161566505065656} is an apocalyptic number.

It is an amenable number.

161566505065656 is an abundant number, since it is smaller than the sum of its proper divisors (286695103019544).

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

161566505065656 is a wasteful number, since it uses less digits than its factorization.

161566505065656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1596229 (or 1596222 counting only the distinct ones).

The product of its (nonzero) digits is 145800000, while the sum is 63.

The spelling of 161566505065656 in words is "one hundred sixty-one trillion, five hundred sixty-six billion, five hundred five million, sixty-five thousand, six hundred fifty-six".