644731241 has 8 divisors (see below), whose sum is σ = 803820864. Its totient is φ = 502387920.

The previous prime is 644731183. The next prime is 644731249. The reversal of 644731241 is 142137446.

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 644731241 - 2¹⁸ = 644469097 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 644731198 and 644731207.

It is not an unprimeable number, because it can be changed into a prime (644731249) 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, 4186490 + ... + 4186643.

It is an arithmetic number, because the mean of its divisors is an integer number (100477608).

Almost surely, 2^644731241 is an apocalyptic number.

It is an amenable number.

644731241 is a deficient number, since it is larger than the sum of its proper divisors (159089623).

644731241 is a wasteful number, since it uses less digits than its factorization.

644731241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8373151.

The product of its digits is 16128, while the sum is 32.

The square root of 644731241 is about 25391.5584594566. The cubic root of 644731241 is about 863.8922373779.

Adding to 644731241 its reverse (142137446), we get a palindrome (786868687).

The spelling of 644731241 in words is "six hundred forty-four million, seven hundred thirty-one thousand, two hundred forty-one".