668200733581 has 2 divisors, whose sum is σ = 668200733582. Its totient is φ = 668200733580.

The previous prime is 668200733533. The next prime is 668200733621. The reversal of 668200733581 is 185337002866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 667627897225 + 572836356 = 817085^2 + 23934^2 .

It is a cyclic number.

It is not a de Polignac number, because 668200733581 - 2²¹ = 668198636429 is a prime.

It is a super-2 number, since 2×668200733581² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668200730581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334100366790 + 334100366791.

It is an arithmetic number, because the mean of its divisors is an integer number (334100366791).

Almost surely, 2^668200733581 is an apocalyptic number.

It is an amenable number.

668200733581 is a deficient number, since it is larger than the sum of its proper divisors (1).

668200733581 is an equidigital number, since it uses as much as digits as its factorization.

668200733581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1451520, while the sum is 49.

The spelling of 668200733581 in words is "six hundred sixty-eight billion, two hundred million, seven hundred thirty-three thousand, five hundred eighty-one".