666873679 has 2 divisors, whose sum is σ = 666873680. Its totient is φ = 666873678.

The previous prime is 666873673. The next prime is 666873703. The reversal of 666873679 is 976378666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 666873679 - 2⁷ = 666873551 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666873673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333436839 + 333436840.

It is an arithmetic number, because the mean of its divisors is an integer number (333436840).

Almost surely, 2^666873679 is an apocalyptic number.

666873679 is a deficient number, since it is larger than the sum of its proper divisors (1).

666873679 is an equidigital number, since it uses as much as digits as its factorization.

666873679 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13716864, while the sum is 58.

The square root of 666873679 is about 25823.8974401619. The cubic root of 666873679 is about 873.6708763440.

The spelling of 666873679 in words is "six hundred sixty-six million, eight hundred seventy-three thousand, six hundred seventy-nine".