644026413 has 8 divisors (see below), whose sum is σ = 903896800. Its totient is φ = 406753488.

The previous prime is 644026387. The next prime is 644026423. The reversal of 644026413 is 314620446.

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

It is not a de Polignac number, because 644026413 - 2¹⁷ = 643895341 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644026423) 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, 5649298 + ... + 5649411.

It is an arithmetic number, because the mean of its divisors is an integer number (112987100).

Almost surely, 2^644026413 is an apocalyptic number.

It is an amenable number.

644026413 is a deficient number, since it is larger than the sum of its proper divisors (259870387).

644026413 is a wasteful number, since it uses less digits than its factorization.

644026413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11298731.

The product of its (nonzero) digits is 13824, while the sum is 30.

The square root of 644026413 is about 25377.6754845671. The cubic root of 644026413 is about 863.5773167733.

Adding to 644026413 its reverse (314620446), we get a palindrome (958646859).

The spelling of 644026413 in words is "six hundred forty-four million, twenty-six thousand, four hundred thirteen".