667901879 has 2 divisors, whose sum is σ = 667901880. Its totient is φ = 667901878.

The previous prime is 667901869. The next prime is 667901881. The reversal of 667901879 is 978109766.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 667901879 - 2⁴ = 667901863 is a prime.

Together with 667901881, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 667901879.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (667901809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333950939 + 333950940.

It is an arithmetic number, because the mean of its divisors is an integer number (333950940).

Almost surely, 2^667901879 is an apocalyptic number.

667901879 is a deficient number, since it is larger than the sum of its proper divisors (1).

667901879 is an equidigital number, since it uses as much as digits as its factorization.

667901879 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1143072, while the sum is 53.

The square root of 667901879 is about 25843.7976891942. The cubic root of 667901879 is about 874.1196605447.

The spelling of 667901879 in words is "six hundred sixty-seven million, nine hundred one thousand, eight hundred seventy-nine".