161811875 has 20 divisors (see below), whose sum is σ = 203372400. Its totient is φ = 128700000.

The previous prime is 161811857. The next prime is 161811889. The reversal of 161811875 is 578118161.

It is not a de Polignac number, because 161811875 - 2¹⁶ = 161746339 is a prime.

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 19 ways as a sum of consecutive naturals, for example, 123725 + ... + 125025.

It is an arithmetic number, because the mean of its divisors is an integer number (10168620).

Almost surely, 2^161811875 is an apocalyptic number.

161811875 is a deficient number, since it is larger than the sum of its proper divisors (41560525).

161811875 is an equidigital number, since it uses as much as digits as its factorization.

161811875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1520 (or 1505 counting only the distinct ones).

The product of its digits is 13440, while the sum is 38.

The square root of 161811875 is about 12720.5296666452. The cubic root of 161811875 is about 544.9250801820.

The spelling of 161811875 in words is "one hundred sixty-one million, eight hundred eleven thousand, eight hundred seventy-five".