669667938809 has 2 divisors, whose sum is σ = 669667938810. Its totient is φ = 669667938808.

The previous prime is 669667938721. The next prime is 669667938811. The reversal of 669667938809 is 908839766966.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 656164801600 + 13503137209 = 810040^2 + 116203^2 .

It is a cyclic number.

It is not a de Polignac number, because 669667938809 - 2²⁴ = 669651161593 is a prime.

Together with 669667938811, 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 669667938809.

It is not a weakly prime, because it can be changed into another prime (669667938859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334833969404 + 334833969405.

It is an arithmetic number, because the mean of its divisors is an integer number (334833969405).

Almost surely, 2^669667938809 is an apocalyptic number.

It is an amenable number.

669667938809 is a deficient number, since it is larger than the sum of its proper divisors (1).

669667938809 is an equidigital number, since it uses as much as digits as its factorization.

669667938809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1269789696, while the sum is 77.

The spelling of 669667938809 in words is "six hundred sixty-nine billion, six hundred sixty-seven million, nine hundred thirty-eight thousand, eight hundred nine".