656728213 has 2 divisors, whose sum is σ = 656728214. Its totient is φ = 656728212.

The previous prime is 656728187. The next prime is 656728243. The reversal of 656728213 is 312827656.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 566535204 + 90193009 = 23802^2 + 9497^2 .

It is a cyclic number.

It is not a de Polignac number, because 656728213 - 2¹³ = 656720021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (656728243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328364106 + 328364107.

It is an arithmetic number, because the mean of its divisors is an integer number (328364107).

Almost surely, 2^656728213 is an apocalyptic number.

It is an amenable number.

656728213 is a deficient number, since it is larger than the sum of its proper divisors (1).

656728213 is an equidigital number, since it uses as much as digits as its factorization.

656728213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 120960, while the sum is 40.

The square root of 656728213 is about 25626.7089771590. The cubic root of 656728213 is about 869.2176932879.

The spelling of 656728213 in words is "six hundred fifty-six million, seven hundred twenty-eight thousand, two hundred thirteen".