644526113 has 16 divisors (see below), whose sum is σ = 845859840. Its totient is φ = 475794000.

The previous prime is 644526107. The next prime is 644526119. The reversal of 644526113 is 311625446.

It is an interprime number because it is at equal distance from previous prime (644526107) and next prime (644526119).

It is not a de Polignac number, because 644526113 - 2⁸ = 644525857 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 644526113.

It is not an unprimeable number, because it can be changed into a prime (644526119) 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, 218813 + ... + 221738.

It is an arithmetic number, because the mean of its divisors is an integer number (52866240).

Almost surely, 2^644526113 is an apocalyptic number.

It is an amenable number.

644526113 is a deficient number, since it is larger than the sum of its proper divisors (201333727).

644526113 is a wasteful number, since it uses less digits than its factorization.

644526113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440588.

The product of its digits is 17280, while the sum is 32.

The square root of 644526113 is about 25387.5188429275. The cubic root of 644526113 is about 863.8006088705.

The spelling of 644526113 in words is "six hundred forty-four million, five hundred twenty-six thousand, one hundred thirteen".