644026468 has 12 divisors (see below), whose sum is σ = 1128395520. Its totient is φ = 321627752.

The previous prime is 644026459. The next prime is 644026499. The reversal of 644026468 is 864620446.

It is a self number, because there is not a number n which added to its sum of digits gives 644026468.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 92596 + ... + 99307.

It is an arithmetic number, because the mean of its divisors is an integer number (94032960).

Almost surely, 2^644026468 is an apocalyptic number.

It is an amenable number.

644026468 is a deficient number, since it is larger than the sum of its proper divisors (484369052).

644026468 is a wasteful number, since it uses less digits than its factorization.

644026468 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192746 (or 192744 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 40.

The square root of 644026468 is about 25377.6765681967. The cubic root of 644026468 is about 863.5773413565.

The spelling of 644026468 in words is "six hundred forty-four million, twenty-six thousand, four hundred sixty-eight".