161189520 has 80 divisors (see below), whose sum is σ = 521430912. Its totient is φ = 41113600.

The previous prime is 161189513. The next prime is 161189531. The reversal of 161189520 is 25981161.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×161189520² = 51964122715660800, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9081 + ... + 20120.

Almost surely, 2^161189520 is an apocalyptic number.

161189520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161189520 is an abundant number, since it is smaller than the sum of its proper divisors (360241392).

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

161189520 is a wasteful number, since it uses less digits than its factorization.

161189520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29240 (or 29234 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 33.

The square root of 161189520 is about 12696.0434781864. The cubic root of 161189520 is about 544.2255588569.

The spelling of 161189520 in words is "one hundred sixty-one million, one hundred eighty-nine thousand, five hundred twenty".