161185900 has 36 divisors (see below), whose sum is σ = 353258640. Its totient is φ = 63832000.

The previous prime is 161185859. The next prime is 161185901. The reversal of 161185900 is 9581161.

It is not an unprimeable number, because it can be changed into a prime (161185901) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2121 + ... + 18079.

It is an arithmetic number, because the mean of its divisors is an integer number (9812740).

Almost surely, 2^161185900 is an apocalyptic number.

161185900 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161185900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (176629320).

161185900 is an abundant number, since it is smaller than the sum of its proper divisors (192072740).

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

161185900 is a wasteful number, since it uses less digits than its factorization.

161185900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16074 (or 16067 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 31.

The square root of 161185900 is about 12695.9009132869. The cubic root of 161185900 is about 544.2214847473.

The spelling of 161185900 in words is "one hundred sixty-one million, one hundred eighty-five thousand, nine hundred".