6440213669 has 2 divisors, whose sum is σ = 6440213670. Its totient is φ = 6440213668.

The previous prime is 6440213641. The next prime is 6440213687. The reversal of 6440213669 is 9663120446.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6069189025 + 371024644 = 77905^2 + 19262^2 .

It is a cyclic number.

It is not a de Polignac number, because 6440213669 - 2³² = 2145246373 is a prime.

It is a super-2 number, since 2×6440213669² = 82952704204748883122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6440213069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3220106834 + 3220106835.

It is an arithmetic number, because the mean of its divisors is an integer number (3220106835).

Almost surely, 2^6440213669 is an apocalyptic number.

It is an amenable number.

6440213669 is a deficient number, since it is larger than the sum of its proper divisors (1).

6440213669 is an equidigital number, since it uses as much as digits as its factorization.

6440213669 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 186624, while the sum is 41.

The square root of 6440213669 is about 80250.9418574013. The cubic root of 6440213669 is about 1860.5160695604.

The spelling of 6440213669 in words is "six billion, four hundred forty million, two hundred thirteen thousand, six hundred sixty-nine".