161636605623 has 16 divisors (see below), whose sum is σ = 241930318560. Its totient is φ = 106646830848.

The previous prime is 161636605619. The next prime is 161636605631. The reversal of 161636605623 is 326506636161.

161636605623 is a `hidden beast` number, since 1 + 6 + 1 + 6 + 36 + 605 + 6 + 2 + 3 = 666.

It is not a de Polignac number, because 161636605623 - 2² = 161636605619 is a prime.

It is a super-2 number, since 2×161636605623² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161636605673) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30855840 + ... + 30861077.

It is an arithmetic number, because the mean of its divisors is an integer number (15120644910).

Almost surely, 2^161636605623 is an apocalyptic number.

161636605623 is a deficient number, since it is larger than the sum of its proper divisors (80293712937).

161636605623 is an equidigital number, since it uses as much as digits as its factorization.

161636605623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61717023 (or 61717017 counting only the distinct ones).

The product of its (nonzero) digits is 699840, while the sum is 45.

The spelling of 161636605623 in words is "one hundred sixty-one billion, six hundred thirty-six million, six hundred five thousand, six hundred twenty-three".