644515051 has 2 divisors, whose sum is σ = 644515052. Its totient is φ = 644515050.

The previous prime is 644515019. The next prime is 644515057. The reversal of 644515051 is 150515446.

644515051 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644515051 - 2⁵ = 644515019 is a prime.

It is not a weakly prime, because it can be changed into another prime (644515057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322257525 + 322257526.

It is an arithmetic number, because the mean of its divisors is an integer number (322257526).

Almost surely, 2^644515051 is an apocalyptic number.

644515051 is a deficient number, since it is larger than the sum of its proper divisors (1).

644515051 is an equidigital number, since it uses as much as digits as its factorization.

644515051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12000, while the sum is 31.

The square root of 644515051 is about 25387.3009790328. The cubic root of 644515051 is about 863.7956670397.

The spelling of 644515051 in words is "six hundred forty-four million, five hundred fifteen thousand, fifty-one".