644614036 has 12 divisors (see below), whose sum is σ = 1230626880. Its totient is φ = 293006360.

The previous prime is 644614021. The next prime is 644614039. The reversal of 644614036 is 630416446.

It is a junction number, because it is equal to n+sod(n) for n = 644613992 and 644614010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644614039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7325116 + ... + 7325203.

It is an arithmetic number, because the mean of its divisors is an integer number (102552240).

Almost surely, 2^644614036 is an apocalyptic number.

It is an amenable number.

644614036 is a deficient number, since it is larger than the sum of its proper divisors (586012844).

644614036 is a wasteful number, since it uses less digits than its factorization.

644614036 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14650334 (or 14650332 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 34.

The square root of 644614036 is about 25389.2504024833. The cubic root of 644614036 is about 863.8398855247.

The spelling of 644614036 in words is "six hundred forty-four million, six hundred fourteen thousand, thirty-six".