644998330 has 16 divisors (see below), whose sum is σ = 1161461664. Its totient is φ = 257896080.

The previous prime is 644998327. The next prime is 644998331. The reversal of 644998330 is 33899446.

It is not an unprimeable number, because it can be changed into a prime (644998331) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16525 + ... + 39535.

It is an arithmetic number, because the mean of its divisors is an integer number (72591354).

Almost surely, 2^644998330 is an apocalyptic number.

644998330 is a deficient number, since it is larger than the sum of its proper divisors (516463334).

644998330 is a wasteful number, since it uses less digits than its factorization.

644998330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25821.

The product of its (nonzero) digits is 559872, while the sum is 46.

The square root of 644998330 is about 25396.8173202864. The cubic root of 644998330 is about 864.0115140855.

The spelling of 644998330 in words is "six hundred forty-four million, nine hundred ninety-eight thousand, three hundred thirty".