666966939 has 8 divisors (see below), whose sum is σ = 892596240. Its totient is φ = 442991136.

The previous prime is 666966919. The next prime is 666966941. The reversal of 666966939 is 939669666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 666966939 - 2⁸ = 666966683 is a prime.

It is not an unprimeable number, because it can be changed into a prime (666966919) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 412432 + ... + 414045.

It is an arithmetic number, because the mean of its divisors is an integer number (111574530).

Almost surely, 2^666966939 is an apocalyptic number.

666966939 is a deficient number, since it is larger than the sum of its proper divisors (225629301).

666966939 is a wasteful number, since it uses less digits than its factorization.

666966939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 826749.

The product of its digits is 17006112, while the sum is 60.

The square root of 666966939 is about 25825.7030688421. The cubic root of 666966939 is about 873.7116010722.

The spelling of 666966939 in words is "six hundred sixty-six million, nine hundred sixty-six thousand, nine hundred thirty-nine".