161611556500161 has 24 divisors (see below), whose sum is σ = 241543132783680. Its totient is φ = 104002309436256.

The previous prime is 161611556500109. The next prime is 161611556500183. The reversal of 161611556500161 is 161005655116161.

161611556500161 is a `hidden beast` number, since 1 + 6 + 1 + 61 + 15 + 565 + 0 + 0 + 16 + 1 = 666.

It is not a de Polignac number, because 161611556500161 - 2¹⁵ = 161611556467393 is a prime.

It is a super-2 number, since 2×161611556500161² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161611556502161) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 68843491 + ... + 71152296.

It is an arithmetic number, because the mean of its divisors is an integer number (10064297199320).

Almost surely, 2^{161611556500161} is an apocalyptic number.

It is an amenable number.

161611556500161 is a deficient number, since it is larger than the sum of its proper divisors (79931576283519).

161611556500161 is a wasteful number, since it uses less digits than its factorization.

161611556500161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140000245 (or 140000242 counting only the distinct ones).

The product of its (nonzero) digits is 162000, while the sum is 45.

The spelling of 161611556500161 in words is "one hundred sixty-one trillion, six hundred eleven billion, five hundred fifty-six million, five hundred thousand, one hundred sixty-one".