644910424399 has 16 divisors (see below), whose sum is σ = 653108400000. Its totient is φ = 636767802720.

The previous prime is 644910424397. The next prime is 644910424447. The reversal of 644910424399 is 993424019446.

It is a cyclic number.

It is not a de Polignac number, because 644910424399 - 2¹ = 644910424397 is a prime.

It is a super-2 number, since 2×644910424399² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644910424397) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43956837 + ... + 43971505.

It is an arithmetic number, because the mean of its divisors is an integer number (40819275000).

Almost surely, 2^644910424399 is an apocalyptic number.

644910424399 is a deficient number, since it is larger than the sum of its proper divisors (8197975601).

644910424399 is a wasteful number, since it uses less digits than its factorization.

644910424399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16518.

The product of its (nonzero) digits is 6718464, while the sum is 55.

The spelling of 644910424399 in words is "six hundred forty-four billion, nine hundred ten million, four hundred twenty-four thousand, three hundred ninety-nine".