161901988 has 12 divisors (see below), whose sum is σ = 284672752. Its totient is φ = 80566920.

The previous prime is 161901979. The next prime is 161901997. The reversal of 161901988 is 889109161.

It is a happy number.

161901988 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (161901979) and next prime (161901997).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 95070 + ... + 96757.

Almost surely, 2^161901988 is an apocalyptic number.

It is an amenable number.

161901988 is a deficient number, since it is larger than the sum of its proper divisors (122770764).

161901988 is a wasteful number, since it uses less digits than its factorization.

161901988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192042 (or 192040 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 43.

The square root of 161901988 is about 12724.0712038247. The cubic root of 161901988 is about 545.0262176317.

The spelling of 161901988 in words is "one hundred sixty-one million, nine hundred one thousand, nine hundred eighty-eight".