644053453 has 2 divisors, whose sum is σ = 644053454. Its totient is φ = 644053452.

The previous prime is 644053447. The next prime is 644053457. The reversal of 644053453 is 354350446.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 450203524 + 193849929 = 21218^2 + 13923^2 .

It is a cyclic number.

It is not a de Polignac number, because 644053453 - 2²⁹ = 107182541 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644053457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322026726 + 322026727.

It is an arithmetic number, because the mean of its divisors is an integer number (322026727).

Almost surely, 2^644053453 is an apocalyptic number.

It is an amenable number.

644053453 is a deficient number, since it is larger than the sum of its proper divisors (1).

644053453 is an equidigital number, since it uses as much as digits as its factorization.

644053453 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 86400, while the sum is 34.

The square root of 644053453 is about 25378.2082306848. The cubic root of 644053453 is about 863.5894026150.

The spelling of 644053453 in words is "six hundred forty-four million, fifty-three thousand, four hundred fifty-three".