644937023 has 2 divisors, whose sum is σ = 644937024. Its totient is φ = 644937022.

The previous prime is 644936983. The next prime is 644937049. The reversal of 644937023 is 320739446.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644937023 - 2¹⁰ = 644935999 is a prime.

It is a super-2 number, since 2×644937023² = 831887527272205058, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644937053) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322468511 + 322468512.

It is an arithmetic number, because the mean of its divisors is an integer number (322468512).

Almost surely, 2^644937023 is an apocalyptic number.

644937023 is a deficient number, since it is larger than the sum of its proper divisors (1).

644937023 is an equidigital number, since it uses as much as digits as its factorization.

644937023 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108864, while the sum is 38.

The square root of 644937023 is about 25395.6103096578. The cubic root of 644937023 is about 863.9841384941.

The spelling of 644937023 in words is "six hundred forty-four million, nine hundred thirty-seven thousand, twenty-three".