161973136 has 20 divisors (see below), whose sum is σ = 337963612. Its totient is φ = 74756736.

The previous prime is 161973121. The next prime is 161973137. The reversal of 161973136 is 631379161.

It can be written as a sum of positive squares in 2 ways, for example, as 66324736 + 95648400 = 8144^2 + 9780^2 .

It is a junction number, because it is equal to n+sod(n) for n = 161973095 and 161973104.

It is not an unprimeable number, because it can be changed into a prime (161973137) 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, 389151 + ... + 389566.

Almost surely, 2^161973136 is an apocalyptic number.

161973136 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

161973136 is an abundant number, since it is smaller than the sum of its proper divisors (175990476).

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

161973136 is a wasteful number, since it uses less digits than its factorization.

161973136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 778738 (or 778732 counting only the distinct ones).

The product of its digits is 20412, while the sum is 37.

The square root of 161973136 is about 12726.8667000169. The cubic root of 161973136 is about 545.1060433891.

The spelling of 161973136 in words is "one hundred sixty-one million, nine hundred seventy-three thousand, one hundred thirty-six".