6440840311 has 2 divisors, whose sum is σ = 6440840312. Its totient is φ = 6440840310.

The previous prime is 6440840279. The next prime is 6440840323. The reversal of 6440840311 is 1130480446.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6440840311 - 2⁵ = 6440840279 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6440840111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3220420155 + 3220420156.

It is an arithmetic number, because the mean of its divisors is an integer number (3220420156).

Almost surely, 2^6440840311 is an apocalyptic number.

6440840311 is a deficient number, since it is larger than the sum of its proper divisors (1).

6440840311 is an equidigital number, since it uses as much as digits as its factorization.

6440840311 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 6440840311 is about 80254.8460281371. The cubic root of 6440840311 is about 1860.5764112281.

The spelling of 6440840311 in words is "six billion, four hundred forty million, eight hundred forty thousand, three hundred eleven".