656215748989 has 2 divisors, whose sum is σ = 656215748990. Its totient is φ = 656215748988.

The previous prime is 656215748899. The next prime is 656215749017. The reversal of 656215748989 is 989847512656.

Together with previous prime (656215748899) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 428949023364 + 227266725625 = 654942^2 + 476725^2 .

It is a cyclic number.

It is not a de Polignac number, because 656215748989 - 2²³ = 656207360381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (656215748789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328107874494 + 328107874495.

It is an arithmetic number, because the mean of its divisors is an integer number (328107874495).

Almost surely, 2^656215748989 is an apocalyptic number.

It is an amenable number.

656215748989 is a deficient number, since it is larger than the sum of its proper divisors (1).

656215748989 is an equidigital number, since it uses as much as digits as its factorization.

656215748989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 261273600, while the sum is 70.

The spelling of 656215748989 in words is "six hundred fifty-six billion, two hundred fifteen million, seven hundred forty-eight thousand, nine hundred eighty-nine".