644326037 has 2 divisors, whose sum is σ = 644326038. Its totient is φ = 644326036.

The previous prime is 644326013. The next prime is 644326051. The reversal of 644326037 is 730623446.

644326037 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 631466641 + 12859396 = 25129^2 + 3586^2 .

It is a cyclic number.

It is not a de Polignac number, because 644326037 - 2²⁰ = 643277461 is a prime.

It is a super-2 number, since 2×644326037² = 830312083912250738, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 644325988 and 644326006.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644326057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322163018 + 322163019.

It is an arithmetic number, because the mean of its divisors is an integer number (322163019).

Almost surely, 2^644326037 is an apocalyptic number.

It is an amenable number.

644326037 is a deficient number, since it is larger than the sum of its proper divisors (1).

644326037 is an equidigital number, since it uses as much as digits as its factorization.

644326037 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72576, while the sum is 35.

The square root of 644326037 is about 25383.5780968720. The cubic root of 644326037 is about 863.7112183073.

The spelling of 644326037 in words is "six hundred forty-four million, three hundred twenty-six thousand, thirty-seven".