644959459 has 2 divisors, whose sum is σ = 644959460. Its totient is φ = 644959458.

The previous prime is 644959429. The next prime is 644959477. The reversal of 644959459 is 954959446.

644959459 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 is a cyclic number.

It is not a de Polignac number, because 644959459 - 2⁷ = 644959331 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (644959409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322479729 + 322479730.

It is an arithmetic number, because the mean of its divisors is an integer number (322479730).

Almost surely, 2^644959459 is an apocalyptic number.

644959459 is a deficient number, since it is larger than the sum of its proper divisors (1).

644959459 is an equidigital number, since it uses as much as digits as its factorization.

644959459 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6998400, while the sum is 55.

The square root of 644959459 is about 25396.0520357004. The cubic root of 644959459 is about 863.9941571071.

The spelling of 644959459 in words is "six hundred forty-four million, nine hundred fifty-nine thousand, four hundred fifty-nine".