644474200 has 48 divisors (see below), whose sum is σ = 1510260480. Its totient is φ = 255749760.

The previous prime is 644474197. The next prime is 644474213. The reversal of 644474200 is 2474446.

644474200 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12714 + ... + 38086.

It is an arithmetic number, because the mean of its divisors is an integer number (31463760).

Almost surely, 2^644474200 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 644474200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (755130240).

644474200 is an abundant number, since it is smaller than the sum of its proper divisors (865786280).

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

644474200 is a wasteful number, since it uses less digits than its factorization.

644474200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25516 (or 25507 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 31.

The square root of 644474200 is about 25386.4964104935. The cubic root of 644474200 is about 863.7774168001. Note that the first 3 decimals are identical.

The spelling of 644474200 in words is "six hundred forty-four million, four hundred seventy-four thousand, two hundred".