161880138 has 24 divisors (see below), whose sum is σ = 400846368. Its totient is φ = 46251432.

The previous prime is 161880119. The next prime is 161880139. The reversal of 161880138 is 831088161.

161880138 is a `hidden beast` number, since 1 + 618 + 8 + 0 + 1 + 38 = 666.

It is not an unprimeable number, because it can be changed into a prime (161880139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 642256 + ... + 642507.

It is an arithmetic number, because the mean of its divisors is an integer number (16701932).

Almost surely, 2^161880138 is an apocalyptic number.

161880138 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

161880138 is an abundant number, since it is smaller than the sum of its proper divisors (238966230).

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

161880138 is a wasteful number, since it uses less digits than its factorization.

161880138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1284778 (or 1284775 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 161880138 is about 12723.2125660149. The cubic root of 161880138 is about 545.0016979438.

The spelling of 161880138 in words is "one hundred sixty-one million, eight hundred eighty thousand, one hundred thirty-eight".