644433113 has 8 divisors (see below), whose sum is σ = 672927936. Its totient is φ = 615978000.

The previous prime is 644433109. The next prime is 644433137. The reversal of 644433113 is 311334446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 644433113 - 2² = 644433109 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644433143) 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, 26063 + ... + 44363.

It is an arithmetic number, because the mean of its divisors is an integer number (84115992).

Almost surely, 2^644433113 is an apocalyptic number.

It is an amenable number.

644433113 is a deficient number, since it is larger than the sum of its proper divisors (28494823).

644433113 is a wasteful number, since it uses less digits than its factorization.

644433113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19855.

The product of its digits is 10368, while the sum is 29.

The square root of 644433113 is about 25385.6871681662. The cubic root of 644433113 is about 863.7590603493.

Adding to 644433113 its reverse (311334446), we get a palindrome (955767559).

The spelling of 644433113 in words is "six hundred forty-four million, four hundred thirty-three thousand, one hundred thirteen".