644294000 has 80 divisors (see below), whose sum is σ = 1780499136. Its totient is φ = 220896000.

The previous prime is 644293961. The next prime is 644294011. The reversal of 644294000 is 492446.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×644294000² = 830229516872000000, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9011 + ... + 37010.

Almost surely, 2^644294000 is an apocalyptic number.

It is an amenable number.

644294000 is an abundant number, since it is smaller than the sum of its proper divisors (1136205136).

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

644294000 is a wasteful number, since it uses less digits than its factorization.

644294000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46051 (or 46035 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 29.

The square root of 644294000 is about 25382.9470314225. The cubic root of 644294000 is about 863.6969030004.

The spelling of 644294000 in words is "six hundred forty-four million, two hundred ninety-four thousand".