157891 has 4 divisors (see below), whose sum is σ = 161784. Its totient is φ = 154000.

The previous prime is 157889. The next prime is 157897. The reversal of 157891 is 198751.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 198751 = 7 ⋅28393.

It is a cyclic number.

It is not a de Polignac number, because 157891 - 2¹ = 157889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (157897) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1885 + ... + 1966.

It is an arithmetic number, because the mean of its divisors is an integer number (40446).

2¹⁵⁷⁸⁹¹ is an apocalyptic number.

157891 is a deficient number, since it is larger than the sum of its proper divisors (3893).

157891 is an equidigital number, since it uses as much as digits as its factorization.

157891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3892.

The product of its digits is 2520, while the sum is 31.

The square root of 157891 is about 397.3550050018. The cubic root of 157891 is about 54.0487671023.

The spelling of 157891 in words is "one hundred fifty-seven thousand, eight hundred ninety-one".