665128207 has 2 divisors, whose sum is σ = 665128208. Its totient is φ = 665128206.

The previous prime is 665128187. The next prime is 665128241. The reversal of 665128207 is 702821566.

It is a happy number.

665128207 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665128207 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665128267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332564103 + 332564104.

It is an arithmetic number, because the mean of its divisors is an integer number (332564104).

Almost surely, 2^665128207 is an apocalyptic number.

665128207 is a deficient number, since it is larger than the sum of its proper divisors (1).

665128207 is an equidigital number, since it uses as much as digits as its factorization.

665128207 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40320, while the sum is 37.

The square root of 665128207 is about 25790.0796237623. The cubic root of 665128207 is about 872.9079630070.

The spelling of 665128207 in words is "six hundred sixty-five million, one hundred twenty-eight thousand, two hundred seven".