666731401249 has 2 divisors, whose sum is σ = 666731401250. Its totient is φ = 666731401248.

The previous prime is 666731401229. The next prime is 666731401319. The reversal of 666731401249 is 942104137666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 665581852224 + 1149549025 = 815832^2 + 33905^2 .

It is a cyclic number.

It is not a de Polignac number, because 666731401249 - 2¹⁹ = 666730876961 is a prime.

It is a super-2 number, since 2×666731401249² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (666731401229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333365700624 + 333365700625.

It is an arithmetic number, because the mean of its divisors is an integer number (333365700625).

Almost surely, 2^666731401249 is an apocalyptic number.

It is an amenable number.

666731401249 is a deficient number, since it is larger than the sum of its proper divisors (1).

666731401249 is an equidigital number, since it uses as much as digits as its factorization.

666731401249 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1306368, while the sum is 49.

The spelling of 666731401249 in words is "six hundred sixty-six billion, seven hundred thirty-one million, four hundred one thousand, two hundred forty-nine".