161998900 has 72 divisors (see below), whose sum is σ = 410043200. Its totient is φ = 55530720.

The previous prime is 161998877. The next prime is 161998919. The reversal of 161998900 is 9899161.

161998900 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 31939 + ... + 36661.

Almost surely, 2^161998900 is an apocalyptic number.

161998900 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 161998900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (205021600).

161998900 is an abundant number, since it is smaller than the sum of its proper divisors (248044300).

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

161998900 is a wasteful number, since it uses less digits than its factorization.

161998900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4758 (or 4737 counting only the distinct ones).

The product of its (nonzero) digits is 34992, while the sum is 43.

The square root of 161998900 is about 12727.8788492034. The cubic root of 161998900 is about 545.1349439995.

The spelling of 161998900 in words is "one hundred sixty-one million, nine hundred ninety-eight thousand, nine hundred".