161875891 has 2 divisors, whose sum is σ = 161875892. Its totient is φ = 161875890.

The previous prime is 161875859. The next prime is 161875907. The reversal of 161875891 is 198578161.

161875891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is an emirp because it is prime and its reverse (198578161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161875891 - 2⁵ = 161875859 is a prime.

It is not a weakly prime, because it can be changed into another prime (161855891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80937945 + 80937946.

It is an arithmetic number, because the mean of its divisors is an integer number (80937946).

Almost surely, 2^161875891 is an apocalyptic number.

161875891 is a deficient number, since it is larger than the sum of its proper divisors (1).

161875891 is an equidigital number, since it uses as much as digits as its factorization.

161875891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 46.

The square root of 161875891 is about 12723.0456652486. The cubic root of 161875891 is about 544.9969317786.

The spelling of 161875891 in words is "one hundred sixty-one million, eight hundred seventy-five thousand, eight hundred ninety-one".