656323121 has 8 divisors (see below), whose sum is σ = 673134504. Its totient is φ = 639550080.

The previous prime is 656323091. The next prime is 656323123. The reversal of 656323121 is 121323656.

656323121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 2958400 + 653364721 = 1720^2 + 25561^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-656323121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (656323123) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26831 + ... + 45083.

It is an arithmetic number, because the mean of its divisors is an integer number (84141813).

Almost surely, 2^656323121 is an apocalyptic number.

It is an amenable number.

656323121 is a deficient number, since it is larger than the sum of its proper divisors (16811383).

656323121 is a wasteful number, since it uses less digits than its factorization.

656323121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19171.

The product of its digits is 6480, while the sum is 29.

The square root of 656323121 is about 25618.8040509310. The cubic root of 656323121 is about 869.0389356476.

Adding to 656323121 its reverse (121323656), we get a palindrome (777646777).

The spelling of 656323121 in words is "six hundred fifty-six million, three hundred twenty-three thousand, one hundred twenty-one".