644922413 has 2 divisors, whose sum is σ = 644922414. Its totient is φ = 644922412.

The previous prime is 644922409. The next prime is 644922433. The reversal of 644922413 is 314229446.

644922413 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., 544662244 + 100260169 = 23338^2 + 10013^2 .

It is a cyclic number.

It is not a de Polignac number, because 644922413 - 2² = 644922409 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644922433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322461206 + 322461207.

It is an arithmetic number, because the mean of its divisors is an integer number (322461207).

Almost surely, 2^644922413 is an apocalyptic number.

It is an amenable number.

644922413 is a deficient number, since it is larger than the sum of its proper divisors (1).

644922413 is an equidigital number, since it uses as much as digits as its factorization.

644922413 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 41472, while the sum is 35.

The square root of 644922413 is about 25395.3226598915. The cubic root of 644922413 is about 863.9776143927.

The spelling of 644922413 in words is "six hundred forty-four million, nine hundred twenty-two thousand, four hundred thirteen".