6641568581623 has 2 divisors, whose sum is σ = 6641568581624. Its totient is φ = 6641568581622.

The previous prime is 6641568581611. The next prime is 6641568581629. The reversal of 6641568581623 is 3261858651466.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6641568581623 - 2²¹ = 6641566484471 is a prime.

It is a super-2 number, since 2×6641568581623² (a number of 26 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6641568581629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3320784290811 + 3320784290812.

It is an arithmetic number, because the mean of its divisors is an integer number (3320784290812).

Almost surely, 2^{6641568581623} is an apocalyptic number.

6641568581623 is a deficient number, since it is larger than the sum of its proper divisors (1).

6641568581623 is an equidigital number, since it uses as much as digits as its factorization.

6641568581623 is an evil number, because the sum of its binary digits is even.

The product of its digits is 49766400, while the sum is 61.

The spelling of 6641568581623 in words is "six trillion, six hundred forty-one billion, five hundred sixty-eight million, five hundred eighty-one thousand, six hundred twenty-three".