161557236 has 36 divisors (see below), whose sum is σ = 417074112. Its totient is φ = 52706064.

The previous prime is 161557229. The next prime is 161557237. The reversal of 161557236 is 632755161.

161557236 is a `hidden beast` number, since 1 + 615 + 5 + 7 + 2 + 36 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×161557236² = 52201481007919392, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 161557236.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161557237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 46050 + ... + 49433.

It is an arithmetic number, because the mean of its divisors is an integer number (11585392).

Almost surely, 2^161557236 is an apocalyptic number.

It is an amenable number.

161557236 is an abundant number, since it is smaller than the sum of its proper divisors (255516876).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161557236 is a wasteful number, since it uses less digits than its factorization.

161557236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95540 (or 95535 counting only the distinct ones).

The product of its digits is 37800, while the sum is 36.

The square root of 161557236 is about 12710.5167479532. The cubic root of 161557236 is about 544.6390854564.

The spelling of 161557236 in words is "one hundred sixty-one million, five hundred fifty-seven thousand, two hundred thirty-six".