666696959 has 4 divisors (see below), whose sum is σ = 671493480. Its totient is φ = 661900440.

The previous prime is 666696931. The next prime is 666696977. The reversal of 666696959 is 959696666.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666696959 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666692959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2398052 + ... + 2398329.

It is an arithmetic number, because the mean of its divisors is an integer number (167873370).

Almost surely, 2^666696959 is an apocalyptic number.

666696959 is a deficient number, since it is larger than the sum of its proper divisors (4796521).

666696959 is a wasteful number, since it uses less digits than its factorization.

666696959 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4796520.

The product of its digits is 28343520, while the sum is 62.

The square root of 666696959 is about 25820.4755765652. The cubic root of 666696959 is about 873.5936959312.

The spelling of 666696959 in words is "six hundred sixty-six million, six hundred ninety-six thousand, nine hundred fifty-nine".