666575771 has 2 divisors, whose sum is σ = 666575772. Its totient is φ = 666575770.

The previous prime is 666575743. The next prime is 666575779. The reversal of 666575771 is 177575666.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666575771 is a prime.

It is not a weakly prime, because it can be changed into another prime (666575779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333287885 + 333287886.

It is an arithmetic number, because the mean of its divisors is an integer number (333287886).

Almost surely, 2^666575771 is an apocalyptic number.

666575771 is a deficient number, since it is larger than the sum of its proper divisors (1).

666575771 is an equidigital number, since it uses as much as digits as its factorization.

666575771 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1852200, while the sum is 50.

The square root of 666575771 is about 25818.1287276983. The cubic root of 666575771 is about 873.5407605924.

The spelling of 666575771 in words is "six hundred sixty-six million, five hundred seventy-five thousand, seven hundred seventy-one".