644383404 has 192 divisors, whose sum is σ = 2032665600. Its totient is φ = 172440576.

The previous prime is 644383357. The next prime is 644383447. The reversal of 644383404 is 404383446.

644383404 is a `hidden beast` number, since 644 + 3 + 8 + 3 + 4 + 0 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1622934 + ... + 1623330.

It is an arithmetic number, because the mean of its divisors is an integer number (10586800).

Almost surely, 2^644383404 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644383404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1016332800).

644383404 is an abundant number, since it is smaller than the sum of its proper divisors (1388282196).

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

644383404 is a wasteful number, since it uses less digits than its factorization.

644383404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 549 (or 541 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 36.

The square root of 644383404 is about 25384.7080739567. The cubic root of 644383404 is about 863.7368508019.

The spelling of 644383404 in words is "six hundred forty-four million, three hundred eighty-three thousand, four hundred four".