666605651629 has 2 divisors, whose sum is σ = 666605651630. Its totient is φ = 666605651628.

The previous prime is 666605651623. The next prime is 666605651687. The reversal of 666605651629 is 926156506666.

666605651629 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an a-pointer prime, because the next prime (666605651687) can be obtained adding 666605651629 to its sum of digits (58).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 468714129129 + 197891522500 = 684627^2 + 444850^2 .

It is a cyclic number.

It is not a de Polignac number, because 666605651629 - 2¹³ = 666605643437 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666605651623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333302825814 + 333302825815.

It is an arithmetic number, because the mean of its divisors is an integer number (333302825815).

Almost surely, 2^666605651629 is an apocalyptic number.

It is an amenable number.

666605651629 is a deficient number, since it is larger than the sum of its proper divisors (1).

666605651629 is an equidigital number, since it uses as much as digits as its factorization.

666605651629 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20995200, while the sum is 58.

The spelling of 666605651629 in words is "six hundred sixty-six billion, six hundred five million, six hundred fifty-one thousand, six hundred twenty-nine".