666062591 has 2 divisors, whose sum is σ = 666062592. Its totient is φ = 666062590.

The previous prime is 666062539. The next prime is 666062597. The reversal of 666062591 is 195260666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 666062591 - 2¹⁴ = 666046207 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666062597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333031295 + 333031296.

It is an arithmetic number, because the mean of its divisors is an integer number (333031296).

Almost surely, 2^666062591 is an apocalyptic number.

666062591 is a deficient number, since it is larger than the sum of its proper divisors (1).

666062591 is an equidigital number, since it uses as much as digits as its factorization.

666062591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 116640, while the sum is 41.

The square root of 666062591 is about 25808.1884486300. The cubic root of 666062591 is about 873.3165306513.

The spelling of 666062591 in words is "six hundred sixty-six million, sixty-two thousand, five hundred ninety-one".