161637156 has 36 divisors (see below), whose sum is σ = 432618732. Its totient is φ = 50709504.

The previous prime is 161637149. The next prime is 161637191. The reversal of 161637156 is 651736161.

161637156 is a `hidden beast` number, since 1 + 6 + 1 + 637 + 15 + 6 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 53144100 + 108493056 = 7290^2 + 10416^2 .

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

It is a super-2 number, since 2×161637156² = 52253140399536672, 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 161637156.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 131445 + ... + 132668.

It is an arithmetic number, because the mean of its divisors is an integer number (12017187).

Almost surely, 2^161637156 is an apocalyptic number.

It is an amenable number.

161637156 is an abundant number, since it is smaller than the sum of its proper divisors (270981576).

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

161637156 is a wasteful number, since it uses less digits than its factorization.

161637156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 264140 (or 264135 counting only the distinct ones).

The product of its digits is 22680, while the sum is 36.

The square root of 161637156 is about 12713.6602125430. The cubic root of 161637156 is about 544.7288789795.

The spelling of 161637156 in words is "one hundred sixty-one million, six hundred thirty-seven thousand, one hundred fifty-six".