644024604 has 12 divisors (see below), whose sum is σ = 1502724104. Its totient is φ = 214674864.

The previous prime is 644024603. The next prime is 644024609. The reversal of 644024604 is 406420446.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-3 number, since 3×644024604³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644024603) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26834347 + ... + 26834370.

Almost surely, 2^644024604 is an apocalyptic number.

It is an amenable number.

644024604 is an abundant number, since it is smaller than the sum of its proper divisors (858699500).

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

644024604 is a wasteful number, since it uses less digits than its factorization.

644024604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53668724 (or 53668722 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 30.

The square root of 644024604 is about 25377.6398429799. The cubic root of 644024604 is about 863.5765082077.

It can be divided in two parts, 64402 and 4604, that added together give a triangular number (69006 = T₃₇₁).

The spelling of 644024604 in words is "six hundred forty-four million, twenty-four thousand, six hundred four".