644383398 has 16 divisors (see below), whose sum is σ = 1289100096. Its totient is φ = 214738920.

The previous prime is 644383357. The next prime is 644383447. The reversal of 644383398 is 893383446.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16293 + ... + 39423.

It is an arithmetic number, because the mean of its divisors is an integer number (80568756).

Almost surely, 2^644383398 is an apocalyptic number.

644383398 is an abundant number, since it is smaller than the sum of its proper divisors (644716698).

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

644383398 is a wasteful number, since it uses less digits than its factorization.

644383398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27779.

The product of its digits is 1492992, while the sum is 48.

The square root of 644383398 is about 25384.7079557753. The cubic root of 644383398 is about 863.7368481211.

Adding to 644383398 its sum of digits (48), we get a palindrome (644383446).

The spelling of 644383398 in words is "six hundred forty-four million, three hundred eighty-three thousand, three hundred ninety-eight".