157656621 has 4 divisors (see below), whose sum is σ = 210208832. Its totient is φ = 105104412.

The previous prime is 157656613. The next prime is 157656637. The reversal of 157656621 is 126656751.

157656621 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 a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 157656621 - 2³ = 157656613 is a prime.

It is a super-2 number, since 2×157656621² = 49711220290275282, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 157656621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (157656671) 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, 26276101 + ... + 26276106.

It is an arithmetic number, because the mean of its divisors is an integer number (52552208).

Almost surely, 2^157656621 is an apocalyptic number.

It is an amenable number.

157656621 is a deficient number, since it is larger than the sum of its proper divisors (52552211).

157656621 is an equidigital number, since it uses as much as digits as its factorization.

157656621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52552210.

The product of its digits is 75600, while the sum is 39.

The square root of 157656621 is about 12556.1387775064. The cubic root of 157656621 is about 540.2200988921.

The spelling of 157656621 in words is "one hundred fifty-seven million, six hundred fifty-six thousand, six hundred twenty-one".