156790991 has 4 divisors (see below), whose sum is σ = 179189712. Its totient is φ = 134392272.

The previous prime is 156790981. The next prime is 156790993. The reversal of 156790991 is 199097651.

156790991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 199097651 = 1289 ⋅154459.

It is not a de Polignac number, because 156790991 - 2²² = 152596687 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (156790993) 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, 11199350 + ... + 11199363.

It is an arithmetic number, because the mean of its divisors is an integer number (44797428).

Almost surely, 2^156790991 is an apocalyptic number.

156790991 is a deficient number, since it is larger than the sum of its proper divisors (22398721).

156790991 is an equidigital number, since it uses as much as digits as its factorization.

156790991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22398720.

The product of its (nonzero) digits is 153090, while the sum is 47.

The square root of 156790991 is about 12521.6209413957. The cubic root of 156790991 is about 539.2295723504.

The spelling of 156790991 in words is "one hundred fifty-six million, seven hundred ninety thousand, nine hundred ninety-one".