66869879 has 2 divisors, whose sum is σ = 66869880. Its totient is φ = 66869878.

The previous prime is 66869839. The next prime is 66869917. The reversal of 66869879 is 97896866.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66869879 - 2²⁰ = 65821303 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66869839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33434939 + 33434940.

It is an arithmetic number, because the mean of its divisors is an integer number (33434940).

Almost surely, 2^66869879 is an apocalyptic number.

66869879 is a deficient number, since it is larger than the sum of its proper divisors (1).

66869879 is an equidigital number, since it uses as much as digits as its factorization.

66869879 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7838208, while the sum is 59.

The square root of 66869879 is about 8177.4005038276. The cubic root of 66869879 is about 405.8917079553.

The spelling of 66869879 in words is "sixty-six million, eight hundred sixty-nine thousand, eight hundred seventy-nine".