666946279 has 2 divisors, whose sum is σ = 666946280. Its totient is φ = 666946278.

The previous prime is 666946271. The next prime is 666946289. The reversal of 666946279 is 972649666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 666946279 - 2³ = 666946271 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666946271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333473139 + 333473140.

It is an arithmetic number, because the mean of its divisors is an integer number (333473140).

Almost surely, 2^666946279 is an apocalyptic number.

666946279 is a deficient number, since it is larger than the sum of its proper divisors (1).

666946279 is an equidigital number, since it uses as much as digits as its factorization.

666946279 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5878656, while the sum is 55.

The square root of 666946279 is about 25825.3030766340. The cubic root of 666946279 is about 873.7025796015.

The spelling of 666946279 in words is "six hundred sixty-six million, nine hundred forty-six thousand, two hundred seventy-nine".