644634583 has 2 divisors, whose sum is σ = 644634584. Its totient is φ = 644634582.

The previous prime is 644634541. The next prime is 644634589. The reversal of 644634583 is 385436446.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644634583 - 2¹³ = 644626391 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644634589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322317291 + 322317292.

It is an arithmetic number, because the mean of its divisors is an integer number (322317292).

Almost surely, 2^644634583 is an apocalyptic number.

644634583 is a deficient number, since it is larger than the sum of its proper divisors (1).

644634583 is an equidigital number, since it uses as much as digits as its factorization.

644634583 is an evil number, because the sum of its binary digits is even.

The product of its digits is 829440, while the sum is 43.

The square root of 644634583 is about 25389.6550390115. The cubic root of 644634583 is about 863.8490636936.

The spelling of 644634583 in words is "six hundred forty-four million, six hundred thirty-four thousand, five hundred eighty-three".