667403509 has 2 divisors, whose sum is σ = 667403510. Its totient is φ = 667403508.

The previous prime is 667403483. The next prime is 667403531. The reversal of 667403509 is 905304766.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 390181009 + 277222500 = 19753^2 + 16650^2 .

It is a cyclic number.

It is not a de Polignac number, because 667403509 - 2¹¹ = 667401461 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 (667403609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333701754 + 333701755.

It is an arithmetic number, because the mean of its divisors is an integer number (333701755).

Almost surely, 2^667403509 is an apocalyptic number.

It is an amenable number.

667403509 is a deficient number, since it is larger than the sum of its proper divisors (1).

667403509 is an equidigital number, since it uses as much as digits as its factorization.

667403509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 136080, while the sum is 40.

The square root of 667403509 is about 25834.1539246014. The cubic root of 667403509 is about 873.9021917683.

The spelling of 667403509 in words is "six hundred sixty-seven million, four hundred three thousand, five hundred nine".