667331309 has 2 divisors, whose sum is σ = 667331310. Its totient is φ = 667331308.

The previous prime is 667331303. The next prime is 667331317. The reversal of 667331309 is 903133766.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 653058025 + 14273284 = 25555^2 + 3778^2 .

It is a cyclic number.

It is not a de Polignac number, because 667331309 - 2²⁰ = 666282733 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 (667331303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333665654 + 333665655.

It is an arithmetic number, because the mean of its divisors is an integer number (333665655).

Almost surely, 2^667331309 is an apocalyptic number.

It is an amenable number.

667331309 is a deficient number, since it is larger than the sum of its proper divisors (1).

667331309 is an equidigital number, since it uses as much as digits as its factorization.

667331309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 61236, while the sum is 38.

The square root of 667331309 is about 25832.7565118398. The cubic root of 667331309 is about 873.8706775930.

The spelling of 667331309 in words is "six hundred sixty-seven million, three hundred thirty-one thousand, three hundred nine".