644310677 has 2 divisors, whose sum is σ = 644310678. Its totient is φ = 644310676.

The previous prime is 644310617. The next prime is 644310713. The reversal of 644310677 is 776013446.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 503508721 + 140801956 = 22439^2 + 11866^2 .

It is a cyclic number.

It is not a de Polignac number, because 644310677 - 2²⁰ = 643262101 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 644310677.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644310607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322155338 + 322155339.

It is an arithmetic number, because the mean of its divisors is an integer number (322155339).

Almost surely, 2^644310677 is an apocalyptic number.

It is an amenable number.

644310677 is a deficient number, since it is larger than the sum of its proper divisors (1).

644310677 is an equidigital number, since it uses as much as digits as its factorization.

644310677 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 84672, while the sum is 38.

The square root of 644310677 is about 25383.2755372509. The cubic root of 644310677 is about 863.7043549550.

The spelling of 644310677 in words is "six hundred forty-four million, three hundred ten thousand, six hundred seventy-seven".