161921700 has 72 divisors (see below), whose sum is σ = 520556960. Its totient is φ = 43178400.

The previous prime is 161921699. The next prime is 161921707. The reversal of 161921700 is 7129161.

161921700 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (161921707) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 27286 + ... + 32685.

Almost surely, 2^161921700 is an apocalyptic number.

161921700 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161921700 is an abundant number, since it is smaller than the sum of its proper divisors (358635260).

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

161921700 is a wasteful number, since it uses less digits than its factorization.

161921700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59994 (or 59981 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 27.

The square root of 161921700 is about 12724.8457750968. The cubic root of 161921700 is about 545.0483362005.

The spelling of 161921700 in words is "one hundred sixty-one million, nine hundred twenty-one thousand, seven hundred".