161565616516155 has 32 divisors (see below), whose sum is σ = 259959407685120. Its totient is φ = 85684881638400.

The previous prime is 161565616516067. The next prime is 161565616516163. The reversal of 161565616516155 is 551615616565161.

It is a happy number.

It is not a de Polignac number, because 161565616516155 - 2³⁸ = 161290738609211 is a prime.

It is a super-2 number, since 2×161565616516155² (a number of 29 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 40596121 + ... + 44397930.

It is an arithmetic number, because the mean of its divisors is an integer number (8123731490160).

Almost surely, 2^{161565616516155} is an apocalyptic number.

161565616516155 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

161565616516155 is a deficient number, since it is larger than the sum of its proper divisors (98393791168965).

161565616516155 is a wasteful number, since it uses less digits than its factorization.

161565616516155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84994771.

The product of its digits is 24300000, while the sum is 60.

The spelling of 161565616516155 in words is "one hundred sixty-one trillion, five hundred sixty-five billion, six hundred sixteen million, five hundred sixteen thousand, one hundred fifty-five".