6366542456621 has 2 divisors, whose sum is σ = 6366542456622. Its totient is φ = 6366542456620.

The previous prime is 6366542456567. The next prime is 6366542456639. The reversal of 6366542456621 is 1266542456636.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4428558283396 + 1937984173225 = 2104414^2 + 1392115^2 .

It is a cyclic number.

It is not a de Polignac number, because 6366542456621 - 2¹⁰ = 6366542455597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6366542456821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3183271228310 + 3183271228311.

It is an arithmetic number, because the mean of its divisors is an integer number (3183271228311).

Almost surely, 2^{6366542456621} is an apocalyptic number.

It is an amenable number.

6366542456621 is a deficient number, since it is larger than the sum of its proper divisors (1).

6366542456621 is an equidigital number, since it uses as much as digits as its factorization.

6366542456621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 37324800, while the sum is 56.

The spelling of 6366542456621 in words is "six trillion, three hundred sixty-six billion, five hundred forty-two million, four hundred fifty-six thousand, six hundred twenty-one".