646520807 has 2 divisors, whose sum is σ = 646520808. Its totient is φ = 646520806.

The previous prime is 646520789. The next prime is 646520839. The reversal of 646520807 is 708025646.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 646520807 - 2¹⁸ = 646258663 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646520207) 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, 323260403 + 323260404.

It is an arithmetic number, because the mean of its divisors is an integer number (323260404).

Almost surely, 2^646520807 is an apocalyptic number.

646520807 is a deficient number, since it is larger than the sum of its proper divisors (1).

646520807 is an equidigital number, since it uses as much as digits as its factorization.

646520807 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 80640, while the sum is 38.

The square root of 646520807 is about 25426.7734288092. The cubic root of 646520807 is about 864.6907944030.

It can be divided in two parts, 6465 and 20807, that added together give a palindrome (27272).

The spelling of 646520807 in words is "six hundred forty-six million, five hundred twenty thousand, eight hundred seven".