666905507 has 4 divisors (see below), whose sum is σ = 666959136. Its totient is φ = 666851880.

The previous prime is 666905483. The next prime is 666905557. The reversal of 666905507 is 705509666.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666905507 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666905557) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2582 + ... + 36612.

It is an arithmetic number, because the mean of its divisors is an integer number (166739784).

Almost surely, 2^666905507 is an apocalyptic number.

666905507 is a deficient number, since it is larger than the sum of its proper divisors (53629).

666905507 is a wasteful number, since it uses less digits than its factorization.

666905507 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53628.

The product of its (nonzero) digits is 340200, while the sum is 44.

The square root of 666905507 is about 25824.5136837076. The cubic root of 666905507 is about 873.6847754052.

The spelling of 666905507 in words is "six hundred sixty-six million, nine hundred five thousand, five hundred seven".