667439659 has 2 divisors, whose sum is σ = 667439660. Its totient is φ = 667439658.

The previous prime is 667439609. The next prime is 667439671. The reversal of 667439659 is 956934766.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 667439659 - 2²³ = 659051051 is a prime.

It is not a weakly prime, because it can be changed into another prime (667439609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333719829 + 333719830.

It is an arithmetic number, because the mean of its divisors is an integer number (333719830).

Almost surely, 2^667439659 is an apocalyptic number.

667439659 is a deficient number, since it is larger than the sum of its proper divisors (1).

667439659 is an equidigital number, since it uses as much as digits as its factorization.

667439659 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7348320, while the sum is 55.

The square root of 667439659 is about 25834.8535703224. The cubic root of 667439659 is about 873.9179698264.

The spelling of 667439659 in words is "six hundred sixty-seven million, four hundred thirty-nine thousand, six hundred fifty-nine".