161591564 has 12 divisors (see below), whose sum is σ = 283401888. Its totient is φ = 80619600.

The previous prime is 161591533. The next prime is 161591569. The reversal of 161591564 is 465195161.

It is a super-2 number, since 2×161591564² = 52223667111932192, which contains 22 as substring.

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (161591569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41972 + ... + 45659.

It is an arithmetic number, because the mean of its divisors is an integer number (23616824).

Almost surely, 2^161591564 is an apocalyptic number.

It is an amenable number.

161591564 is a deficient number, since it is larger than the sum of its proper divisors (121810324).

161591564 is a wasteful number, since it uses less digits than its factorization.

161591564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88096 (or 88094 counting only the distinct ones).

The product of its digits is 32400, while the sum is 38.

The square root of 161591564 is about 12711.8670540562. The cubic root of 161591564 is about 544.6776580534.

The spelling of 161591564 in words is "one hundred sixty-one million, five hundred ninety-one thousand, five hundred sixty-four".