156091 has 4 divisors (see below), whose sum is σ = 168112. Its totient is φ = 144072.

The previous prime is 156089. The next prime is 156109. The reversal of 156091 is 190651.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 190651 = 83 ⋅2297.

It is a cyclic number.

It is not a de Polignac number, because 156091 - 2¹ = 156089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (156011) 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, 5991 + ... + 6016.

It is an arithmetic number, because the mean of its divisors is an integer number (42028).

2¹⁵⁶⁰⁹¹ is an apocalyptic number.

156091 is a deficient number, since it is larger than the sum of its proper divisors (12021).

156091 is a wasteful number, since it uses less digits than its factorization.

156091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12020.

The product of its (nonzero) digits is 270, while the sum is 22.

The square root of 156091 is about 395.0835354707. The cubic root of 156091 is about 53.8425914441.

The spelling of 156091 in words is "one hundred fifty-six thousand, ninety-one".