665933987 has 2 divisors, whose sum is σ = 665933988. Its totient is φ = 665933986.

The previous prime is 665933981. The next prime is 665933993. The reversal of 665933987 is 789339566.

665933987 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a balanced prime because it is at equal distance from previous prime (665933981) and next prime (665933993).

It is a cyclic number.

It is not a de Polignac number, because 665933987 - 2⁸ = 665933731 is a prime.

It is not a weakly prime, because it can be changed into another prime (665933981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332966993 + 332966994.

It is an arithmetic number, because the mean of its divisors is an integer number (332966994).

Almost surely, 2^665933987 is an apocalyptic number.

665933987 is a deficient number, since it is larger than the sum of its proper divisors (1).

665933987 is an equidigital number, since it uses as much as digits as its factorization.

665933987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7348320, while the sum is 56.

The square root of 665933987 is about 25805.6967935377. The cubic root of 665933987 is about 873.2603201041.

The spelling of 665933987 in words is "six hundred sixty-five million, nine hundred thirty-three thousand, nine hundred eighty-seven".