656621231 has 4 divisors (see below), whose sum is σ = 750424272. Its totient is φ = 562818192.

The previous prime is 656621221. The next prime is 656621269. The reversal of 656621231 is 132126656.

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 656621231 - 2⁶ = 656621167 is a prime.

It is a super-2 number, since 2×656621231² = 862302881999910722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656621221) 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, 46901510 + ... + 46901523.

It is an arithmetic number, because the mean of its divisors is an integer number (187606068).

Almost surely, 2^656621231 is an apocalyptic number.

656621231 is a deficient number, since it is larger than the sum of its proper divisors (93803041).

656621231 is an equidigital number, since it uses as much as digits as its factorization.

656621231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93803040.

The product of its digits is 12960, while the sum is 32.

The square root of 656621231 is about 25624.6215776936. The cubic root of 656621231 is about 869.1704917743.

Adding to 656621231 its reverse (132126656), we get a palindrome (788747887).

The spelling of 656621231 in words is "six hundred fifty-six million, six hundred twenty-one thousand, two hundred thirty-one".