646243512553 has 2 divisors, whose sum is σ = 646243512554. Its totient is φ = 646243512552.

The previous prime is 646243512521. The next prime is 646243512559. The reversal of 646243512553 is 355215342646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 485151254784 + 161092257769 = 696528^2 + 401363^2 .

It is a cyclic number.

It is not a de Polignac number, because 646243512553 - 2⁵ = 646243512521 is a prime.

It is not a weakly prime, because it can be changed into another prime (646243512559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323121756276 + 323121756277.

It is an arithmetic number, because the mean of its divisors is an integer number (323121756277).

Almost surely, 2^646243512553 is an apocalyptic number.

It is an amenable number.

646243512553 is a deficient number, since it is larger than the sum of its proper divisors (1).

646243512553 is an equidigital number, since it uses as much as digits as its factorization.

646243512553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592000, while the sum is 46.

The spelling of 646243512553 in words is "six hundred forty-six billion, two hundred forty-three million, five hundred twelve thousand, five hundred fifty-three".