644124337 has 4 divisors (see below), whose sum is σ = 644407540. Its totient is φ = 643841136.

The previous prime is 644124289. The next prime is 644124353. The reversal of 644124337 is 733421446.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 492440481 + 151683856 = 22191^2 + 12316^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-644124337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644424337) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 138162 + ... + 142747.

It is an arithmetic number, because the mean of its divisors is an integer number (161101885).

Almost surely, 2^644124337 is an apocalyptic number.

It is an amenable number.

644124337 is a deficient number, since it is larger than the sum of its proper divisors (283203).

644124337 is a wasteful number, since it uses less digits than its factorization.

644124337 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283202.

The product of its digits is 48384, while the sum is 34.

The square root of 644124337 is about 25379.6047447552. The cubic root of 644124337 is about 863.6210834355.

The spelling of 644124337 in words is "six hundred forty-four million, one hundred twenty-four thousand, three hundred thirty-seven".