656212545217 has 2 divisors, whose sum is σ = 656212545218. Its totient is φ = 656212545216.

The previous prime is 656212545179. The next prime is 656212545253. The reversal of 656212545217 is 712545212656.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 655256251441 + 956293776 = 809479^2 + 30924^2 .

It is a cyclic number.

It is not a de Polignac number, because 656212545217 - 2¹⁹ = 656212020929 is a prime.

It is a super-2 number, since 2×656212545217² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (656212545017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328106272608 + 328106272609.

It is an arithmetic number, because the mean of its divisors is an integer number (328106272609).

Almost surely, 2^656212545217 is an apocalyptic number.

It is an amenable number.

656212545217 is a deficient number, since it is larger than the sum of its proper divisors (1).

656212545217 is an equidigital number, since it uses as much as digits as its factorization.

656212545217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1008000, while the sum is 46.

The spelling of 656212545217 in words is "six hundred fifty-six billion, two hundred twelve million, five hundred forty-five thousand, two hundred seventeen".