644214000 has 160 divisors (see below), whose sum is σ = 2186645760. Its totient is φ = 162720000.

The previous prime is 644213971. The next prime is 644214001. The reversal of 644214000 is 412446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644214001) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 111175 + ... + 116825.

It is an arithmetic number, because the mean of its divisors is an integer number (13666536).

Almost surely, 2^644214000 is an apocalyptic number.

644214000 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 644214000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1093322880).

644214000 is an abundant number, since it is smaller than the sum of its proper divisors (1542431760).

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

644214000 is a wasteful number, since it uses less digits than its factorization.

644214000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5696 (or 5680 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

The square root of 644214000 is about 25381.3711213559. The cubic root of 644214000 is about 863.6611539933.

Adding to 644214000 its reverse (412446), we get a palindrome (644626446).

The spelling of 644214000 in words is "six hundred forty-four million, two hundred fourteen thousand".