666492464294621 has 2 divisors, whose sum is σ = 666492464294622. Its totient is φ = 666492464294620.

The previous prime is 666492464294611. The next prime is 666492464294801. The reversal of 666492464294621 is 126492464294666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 663404761656025 + 3087702638596 = 25756645^2 + 1757186^2 .

It is a cyclic number.

It is not a de Polignac number, because 666492464294621 - 2¹⁴ = 666492464278237 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666492464294611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333246232147310 + 333246232147311.

It is an arithmetic number, because the mean of its divisors is an integer number (333246232147311).

Almost surely, 2^{666492464294621} is an apocalyptic number.

It is an amenable number.

666492464294621 is a deficient number, since it is larger than the sum of its proper divisors (1).

666492464294621 is an equidigital number, since it uses as much as digits as its factorization.

666492464294621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1289945088, while the sum is 71.

The spelling of 666492464294621 in words is "six hundred sixty-six trillion, four hundred ninety-two billion, four hundred sixty-four million, two hundred ninety-four thousand, six hundred twenty-one".