6440264641 has 2 divisors, whose sum is σ = 6440264642. Its totient is φ = 6440264640.

The previous prime is 6440264561. The next prime is 6440264689. The reversal of 6440264641 is 1464620446.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3270124225 + 3170140416 = 57185^2 + 56304^2 .

It is a cyclic number.

It is not a de Polignac number, because 6440264641 - 2¹¹ = 6440262593 is a prime.

It is a super-2 number, since 2×6440264641² = 82954017292229717762, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 6440264641.

It is not a weakly prime, because it can be changed into another prime (6440264741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3220132320 + 3220132321.

It is an arithmetic number, because the mean of its divisors is an integer number (3220132321).

Almost surely, 2^6440264641 is an apocalyptic number.

It is an amenable number.

6440264641 is a deficient number, since it is larger than the sum of its proper divisors (1).

6440264641 is an equidigital number, since it uses as much as digits as its factorization.

6440264641 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 110592, while the sum is 37.

The square root of 6440264641 is about 80251.2594356001. The cubic root of 6440264641 is about 1860.5209779884.

The spelling of 6440264641 in words is "six billion, four hundred forty million, two hundred sixty-four thousand, six hundred forty-one".