644725246 has 16 divisors (see below), whose sum is σ = 1080738288. Its totient is φ = 285908800.

The previous prime is 644725217. The next prime is 644725253. The reversal of 644725246 is 642527446.

It is a junction number, because it is equal to n+sod(n) for n = 644725199 and 644725208.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 356485 + ... + 358288.

It is an arithmetic number, because the mean of its divisors is an integer number (67546143).

Almost surely, 2^644725246 is an apocalyptic number.

644725246 is a deficient number, since it is larger than the sum of its proper divisors (436013042).

644725246 is a wasteful number, since it uses less digits than its factorization.

644725246 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 714827.

The product of its digits is 322560, while the sum is 40.

The square root of 644725246 is about 25391.4404081375. The cubic root of 644725246 is about 863.8895597505.

The spelling of 644725246 in words is "six hundred forty-four million, seven hundred twenty-five thousand, two hundred forty-six".