156557401 has 24 divisors (see below), whose sum is σ = 213966144. Its totient is φ = 112603680.

The previous prime is 156557383. The next prime is 156557407. The reversal of 156557401 is 104755651.

It is not a de Polignac number, because 156557401 - 2⁷ = 156557273 is a prime.

It is a Smith number, since the sum of its digits (34) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (156557407) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4165 + ... + 18178.

It is an arithmetic number, because the mean of its divisors is an integer number (8915256).

Almost surely, 2^156557401 is an apocalyptic number.

156557401 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

156557401 is a deficient number, since it is larger than the sum of its proper divisors (57408743).

156557401 is a wasteful number, since it uses less digits than its factorization.

156557401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22381 (or 22374 counting only the distinct ones).

The product of its (nonzero) digits is 21000, while the sum is 34.

The square root of 156557401 is about 12512.2899982377. The cubic root of 156557401 is about 538.9616546623.

The spelling of 156557401 in words is "one hundred fifty-six million, five hundred fifty-seven thousand, four hundred one".