644712899 has 2 divisors, whose sum is σ = 644712900. Its totient is φ = 644712898.

The previous prime is 644712877. The next prime is 644712911. The reversal of 644712899 is 998217446.

644712899 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 644712899 - 2¹⁶ = 644647363 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (644712869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322356449 + 322356450.

It is an arithmetic number, because the mean of its divisors is an integer number (322356450).

Almost surely, 2^644712899 is an apocalyptic number.

644712899 is a deficient number, since it is larger than the sum of its proper divisors (1).

644712899 is an equidigital number, since it uses as much as digits as its factorization.

644712899 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 870912, while the sum is 50.

The square root of 644712899 is about 25391.1972738585. The cubic root of 644712899 is about 863.8840449918.

The spelling of 644712899 in words is "six hundred forty-four million, seven hundred twelve thousand, eight hundred ninety-nine".