165660561615 has 16 divisors (see below), whose sum is σ = 265095439488. Its totient is φ = 88339452576.

The previous prime is 165660561587. The next prime is 165660561631. The reversal of 165660561615 is 516165066561.

It is not a de Polignac number, because 165660561615 - 2¹⁰ = 165660560591 is a prime.

It is a super-2 number, since 2×165660561615² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 695877 + ... + 903086.

It is an arithmetic number, because the mean of its divisors is an integer number (16568464968).

Almost surely, 2^165660561615 is an apocalyptic number.

165660561615 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

165660561615 is a deficient number, since it is larger than the sum of its proper divisors (99434877873).

165660561615 is a wasteful number, since it uses less digits than its factorization.

165660561615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1605878.

The product of its (nonzero) digits is 972000, while the sum is 48.

The spelling of 165660561615 in words is "one hundred sixty-five billion, six hundred sixty million, five hundred sixty-one thousand, six hundred fifteen".