644074039 has 8 divisors (see below), whose sum is σ = 736985600. Its totient is φ = 551387736.

The previous prime is 644074009. The next prime is 644074049. The reversal of 644074039 is 930470446.

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 644074039 - 2⁹ = 644073527 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 644073989 and 644074007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644074009) by changing a digit.

It is a Zeisel number, with parameters (136, -129).

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50139 + ... + 61660.

It is an arithmetic number, because the mean of its divisors is an integer number (92123200).

Almost surely, 2^644074039 is an apocalyptic number.

644074039 is a deficient number, since it is larger than the sum of its proper divisors (92911561).

644074039 is a wasteful number, since it uses less digits than its factorization.

644074039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112629.

The product of its (nonzero) digits is 72576, while the sum is 37.

The square root of 644074039 is about 25378.6138116328. The cubic root of 644074039 is about 863.5986035397.

The spelling of 644074039 in words is "six hundred forty-four million, seventy-four thousand, thirty-nine".