644698395 has 96 divisors (see below), whose sum is σ = 1347300864. Its totient is φ = 281318400.

The previous prime is 644698337. The next prime is 644698403. The reversal of 644698395 is 593896446.

644698395 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 644698395 - 2¹³ = 644690203 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 191880 + ... + 195210.

It is an arithmetic number, because the mean of its divisors is an integer number (14034384).

Almost surely, 2^644698395 is an apocalyptic number.

644698395 is an abundant number, since it is smaller than the sum of its proper divisors (702602469).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644698395 is a wasteful number, since it uses less digits than its factorization.

644698395 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3393 (or 3390 counting only the distinct ones).

The product of its digits is 5598720, while the sum is 54.

The square root of 644698395 is about 25390.9116614587. The cubic root of 644698395 is about 863.8775667242.

The spelling of 644698395 in words is "six hundred forty-four million, six hundred ninety-eight thousand, three hundred ninety-five".