644326036 has 24 divisors (see below), whose sum is σ = 1135451520. Its totient is φ = 319920000.

The previous prime is 644326013. The next prime is 644326037. The reversal of 644326036 is 630623446.

It is a junction number, because it is equal to n+sod(n) for n = 644325992 and 644326010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644326037) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 431980 + ... + 433468.

It is an arithmetic number, because the mean of its divisors is an integer number (47310480).

Almost surely, 2^644326036 is an apocalyptic number.

It is an amenable number.

644326036 is a deficient number, since it is larger than the sum of its proper divisors (491125484).

644326036 is a wasteful number, since it uses less digits than its factorization.

644326036 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2175 (or 2173 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 34.

The square root of 644326036 is about 25383.5780771742. The cubic root of 644326036 is about 863.7112178605.

The spelling of 644326036 in words is "six hundred forty-four million, three hundred twenty-six thousand, thirty-six".