161618836 has 24 divisors (see below), whose sum is σ = 289301544. Its totient is φ = 78973440.

The previous prime is 161618833. The next prime is 161618857. The reversal of 161618836 is 638816161.

It can be written as a sum of positive squares in 4 ways, for example, as 104162436 + 57456400 = 10206^2 + 7580^2 .

It is a super-2 number, since 2×161618836² = 52241296299989792, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161618833) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 58216 + ... + 60928.

It is an arithmetic number, because the mean of its divisors is an integer number (12054231).

Almost surely, 2^161618836 is an apocalyptic number.

It is an amenable number.

161618836 is a deficient number, since it is larger than the sum of its proper divisors (127682708).

161618836 is a wasteful number, since it uses less digits than its factorization.

161618836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3051 (or 3049 counting only the distinct ones).

The product of its digits is 41472, while the sum is 40.

The square root of 161618836 is about 12712.9397072432. The cubic root of 161618836 is about 544.7082982946.

The spelling of 161618836 in words is "one hundred sixty-one million, six hundred eighteen thousand, eight hundred thirty-six".