665138963 has 2 divisors, whose sum is σ = 665138964. Its totient is φ = 665138962.

The previous prime is 665138953. The next prime is 665138977. The reversal of 665138963 is 369831566.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 665138963 - 2⁸ = 665138707 is a prime.

It is not a weakly prime, because it can be changed into another prime (665138953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332569481 + 332569482.

It is an arithmetic number, because the mean of its divisors is an integer number (332569482).

Almost surely, 2^665138963 is an apocalyptic number.

665138963 is a deficient number, since it is larger than the sum of its proper divisors (1).

665138963 is an equidigital number, since it uses as much as digits as its factorization.

665138963 is an evil number, because the sum of its binary digits is even.

The product of its digits is 699840, while the sum is 47.

The square root of 665138963 is about 25790.2881527136. The cubic root of 665138963 is about 872.9126683392.

The spelling of 665138963 in words is "six hundred sixty-five million, one hundred thirty-eight thousand, nine hundred sixty-three".