161511611655 has 32 divisors (see below), whose sum is σ = 269899278336. Its totient is φ = 82319435264.

The previous prime is 161511611627. The next prime is 161511611669. The reversal of 161511611655 is 556116115161.

It is a cyclic number.

It is not a de Polignac number, because 161511611655 - 2¹¹ = 161511609607 is a prime.

It is a congruent number.

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, 168319 + ... + 592751.

It is an arithmetic number, because the mean of its divisors is an integer number (8434352448).

Almost surely, 2^161511611655 is an apocalyptic number.

161511611655 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

161511611655 is a deficient number, since it is larger than the sum of its proper divisors (108387666681).

161511611655 is a wasteful number, since it uses less digits than its factorization.

161511611655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 425567.

The product of its digits is 27000, while the sum is 39.

The spelling of 161511611655 in words is "one hundred sixty-one billion, five hundred eleven million, six hundred eleven thousand, six hundred fifty-five".