646579634237 has 2 divisors, whose sum is σ = 646579634238. Its totient is φ = 646579634236.

The previous prime is 646579634177. The next prime is 646579634251. The reversal of 646579634237 is 732436975646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 415852157956 + 230727476281 = 644866^2 + 480341^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646579634237 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 646579634237.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646579634537) 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, 323289817118 + 323289817119.

It is an arithmetic number, because the mean of its divisors is an integer number (323289817119).

Almost surely, 2^646579634237 is an apocalyptic number.

It is an amenable number.

646579634237 is a deficient number, since it is larger than the sum of its proper divisors (1).

646579634237 is an equidigital number, since it uses as much as digits as its factorization.

646579634237 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 137168640, while the sum is 62.

The spelling of 646579634237 in words is "six hundred forty-six billion, five hundred seventy-nine million, six hundred thirty-four thousand, two hundred thirty-seven".