156128231 has 4 divisors (see below), whose sum is σ = 178432272. Its totient is φ = 133824192.

The previous prime is 156128207. The next prime is 156128233. The reversal of 156128231 is 132821651.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 156128231 - 2²⁶ = 89019367 is a prime.

It is a super-2 number, since 2×156128231² = 48752049030378722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 156128194 and 156128203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (156128233) 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, 11152010 + ... + 11152023.

It is an arithmetic number, because the mean of its divisors is an integer number (44608068).

Almost surely, 2^156128231 is an apocalyptic number.

156128231 is a deficient number, since it is larger than the sum of its proper divisors (22304041).

156128231 is an equidigital number, since it uses as much as digits as its factorization.

156128231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22304040.

The product of its digits is 2880, while the sum is 29.

The square root of 156128231 is about 12495.1282906579. The cubic root of 156128231 is about 538.4687196881.

Adding to 156128231 its reverse (132821651), we get a palindrome (288949882).

It can be divided in two parts, 1561 and 28231, that added together give a palindrome (29792).

The spelling of 156128231 in words is "one hundred fifty-six million, one hundred twenty-eight thousand, two hundred thirty-one".