646504997 has 2 divisors, whose sum is σ = 646504998. Its totient is φ = 646504996.

The previous prime is 646504987. The next prime is 646505047. The reversal of 646504997 is 799405646.

It is an a-pointer prime, because the next prime (646505047) can be obtained adding 646504997 to its sum of digits (50).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 612760516 + 33744481 = 24754^2 + 5809^2 .

It is a cyclic number.

It is not a de Polignac number, because 646504997 - 2¹² = 646500901 is a prime.

It is a super-2 number, since 2×646504997² = 835937422291940018, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646504927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323252498 + 323252499.

It is an arithmetic number, because the mean of its divisors is an integer number (323252499).

Almost surely, 2^646504997 is an apocalyptic number.

It is an amenable number.

646504997 is a deficient number, since it is larger than the sum of its proper divisors (1).

646504997 is an equidigital number, since it uses as much as digits as its factorization.

646504997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1632960, while the sum is 50.

The square root of 646504997 is about 25426.4625341395. The cubic root of 646504997 is about 864.6837459715.

The spelling of 646504997 in words is "six hundred forty-six million, five hundred four thousand, nine hundred ninety-seven".