644974583453 has 2 divisors, whose sum is σ = 644974583454. Its totient is φ = 644974583452.

The previous prime is 644974583437. The next prime is 644974583479. The reversal of 644974583453 is 354385479446.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 535901594809 + 109072988644 = 732053^2 + 330262^2 .

It is a cyclic number.

It is not a de Polignac number, because 644974583453 - 2⁴ = 644974583437 is a prime.

It is a super-2 number, since 2×644974583453² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644974583153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322487291726 + 322487291727.

It is an arithmetic number, because the mean of its divisors is an integer number (322487291727).

Almost surely, 2^644974583453 is an apocalyptic number.

It is an amenable number.

644974583453 is a deficient number, since it is larger than the sum of its proper divisors (1).

644974583453 is an equidigital number, since it uses as much as digits as its factorization.

644974583453 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 174182400, while the sum is 62.

The spelling of 644974583453 in words is "six hundred forty-four billion, nine hundred seventy-four million, five hundred eighty-three thousand, four hundred fifty-three".