161638156 has 12 divisors (see below), whose sum is σ = 283006192. Its totient is φ = 80779248.

The previous prime is 161638121. The next prime is 161638157. The reversal of 161638156 is 651836161.

It is a super-2 number, since 2×161638156² = 52253786950160672, which contains 22 as substring.

It is a hoax number, since the sum of its digits (37) 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 (161638157) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 361 + ... + 17983.

Almost surely, 2^161638156 is an apocalyptic number.

It is an amenable number.

161638156 is a deficient number, since it is larger than the sum of its proper divisors (121368036).

161638156 is a wasteful number, since it uses less digits than its factorization.

161638156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19920 (or 19918 counting only the distinct ones).

The product of its digits is 25920, while the sum is 37.

The square root of 161638156 is about 12713.6995402597. The cubic root of 161638156 is about 544.7300023345.

The spelling of 161638156 in words is "one hundred sixty-one million, six hundred thirty-eight thousand, one hundred fifty-six".