644241600 has 252 divisors, whose sum is σ = 2376026744. Its totient is φ = 171694080.

The previous prime is 644241593. The next prime is 644241613. The reversal of 644241600 is 6142446.

644241600 is a `hidden beast` number, since 644 + 2 + 4 + 16 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 387972 + ... + 389628.

Almost surely, 2^644241600 is an apocalyptic number.

644241600 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644241600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1188013372).

644241600 is an abundant number, since it is smaller than the sum of its proper divisors (1731785144).

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

644241600 is a wasteful number, since it uses less digits than its factorization.

644241600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1694 (or 1667 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 644241600 is about 25381.9148213841. The cubic root of 644241600 is about 863.6734877352.

The spelling of 644241600 in words is "six hundred forty-four million, two hundred forty-one thousand, six hundred".