161155565601 has 32 divisors (see below), whose sum is σ = 235525708800. Its totient is φ = 97561282560.

The previous prime is 161155565581. The next prime is 161155565603. The reversal of 161155565601 is 106565551161.

It is not a de Polignac number, because 161155565601 - 2⁵ = 161155565569 is a prime.

It is a super-2 number, since 2×161155565601² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161155565603) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2090421 + ... + 2166141.

It is an arithmetic number, because the mean of its divisors is an integer number (7360178400).

Almost surely, 2^161155565601 is an apocalyptic number.

It is an amenable number.

161155565601 is a deficient number, since it is larger than the sum of its proper divisors (74370143199).

161155565601 is a wasteful number, since it uses less digits than its factorization.

161155565601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77209.

The product of its (nonzero) digits is 135000, while the sum is 42.

The spelling of 161155565601 in words is "one hundred sixty-one billion, one hundred fifty-five million, five hundred sixty-five thousand, six hundred one".