156393921 has 16 divisors (see below), whose sum is σ = 221451840. Its totient is φ = 97896960.

The previous prime is 156393889. The next prime is 156393961. The reversal of 156393921 is 129393651.

It is not a de Polignac number, because 156393921 - 2⁵ = 156393889 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 156393921.

It is not an unprimeable number, because it can be changed into a prime (156393961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5700 + ... + 18581.

It is an arithmetic number, because the mean of its divisors is an integer number (13840740).

Almost surely, 2^156393921 is an apocalyptic number.

It is an amenable number.

156393921 is a deficient number, since it is larger than the sum of its proper divisors (65057919).

156393921 is a wasteful number, since it uses less digits than its factorization.

156393921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24416.

The product of its digits is 43740, while the sum is 39.

The square root of 156393921 is about 12505.7555149619. The cubic root of 156393921 is about 538.7739915709.

It can be divided in two parts, 15 and 6393921, that added together give a palindrome (6393936).

The spelling of 156393921 in words is "one hundred fifty-six million, three hundred ninety-three thousand, nine hundred twenty-one".