644349108 has 48 divisors (see below), whose sum is σ = 1620920000. Its totient is φ = 198042624.

The previous prime is 644349107. The next prime is 644349119. The reversal of 644349108 is 801943446.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644349103) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 193191 + ... + 196497.

Almost surely, 2^644349108 is an apocalyptic number.

It is an amenable number.

644349108 is an abundant number, since it is smaller than the sum of its proper divisors (976570892).

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

644349108 is a wasteful number, since it uses less digits than its factorization.

644349108 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4576 (or 4574 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 39.

The square root of 644349108 is about 25384.0325401619. The cubic root of 644349108 is about 863.7215269826.

The spelling of 644349108 in words is "six hundred forty-four million, three hundred forty-nine thousand, one hundred eight".