644411311 has 2 divisors, whose sum is σ = 644411312. Its totient is φ = 644411310.

The previous prime is 644411237. The next prime is 644411323. The reversal of 644411311 is 113114446.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644411311 - 2²⁵ = 610856879 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644411111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322205655 + 322205656.

It is an arithmetic number, because the mean of its divisors is an integer number (322205656).

Almost surely, 2^644411311 is an apocalyptic number.

644411311 is a deficient number, since it is larger than the sum of its proper divisors (1).

644411311 is an equidigital number, since it uses as much as digits as its factorization.

644411311 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1152, while the sum is 25.

The square root of 644411311 is about 25385.2577493316. The cubic root of 644411311 is about 863.7493195466.

Adding to 644411311 its reverse (113114446), we get a palindrome (757525757).

The spelling of 644411311 in words is "six hundred forty-four million, four hundred eleven thousand, three hundred eleven".