646202253509 has 2 divisors, whose sum is σ = 646202253510. Its totient is φ = 646202253508.

The previous prime is 646202253503. The next prime is 646202253547. The reversal of 646202253509 is 905352202646.

646202253509 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 644118604900 + 2083648609 = 802570^2 + 45647^2 .

It is a cyclic number.

It is not a de Polignac number, because 646202253509 - 2²⁸ = 645933818053 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 646202253509.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646202253503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323101126754 + 323101126755.

It is an arithmetic number, because the mean of its divisors is an integer number (323101126755).

Almost surely, 2^646202253509 is an apocalyptic number.

It is an amenable number.

646202253509 is a deficient number, since it is larger than the sum of its proper divisors (1).

646202253509 is an equidigital number, since it uses as much as digits as its factorization.

646202253509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 777600, while the sum is 44.

The spelling of 646202253509 in words is "six hundred forty-six billion, two hundred two million, two hundred fifty-three thousand, five hundred nine".