644334000 has 160 divisors (see below), whose sum is σ = 2199877056. Its totient is φ = 161689600.

The previous prime is 644333993. The next prime is 644334011. The reversal of 644334000 is 433446.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 98842 + ... + 105158.

Almost surely, 2^644334000 is an apocalyptic number.

644334000 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 644334000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1099938528).

644334000 is an abundant number, since it is smaller than the sum of its proper divisors (1555543056).

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

644334000 is a wasteful number, since it uses less digits than its factorization.

644334000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6360 (or 6344 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 24.

The square root of 644334000 is about 25383.7349497666. The cubic root of 644334000 is about 863.7147763942.

Adding to 644334000 its reverse (433446), we get a palindrome (644767446).

The spelling of 644334000 in words is "six hundred forty-four million, three hundred thirty-four thousand".