666887806 has 64 divisors (see below), whose sum is σ = 1158312960. Its totient is φ = 285626880.

The previous prime is 666887789. The next prime is 666887863. The reversal of 666887806 is 608788666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4797685 + ... + 4797823.

It is an arithmetic number, because the mean of its divisors is an integer number (18098640).

Almost surely, 2^666887806 is an apocalyptic number.

666887806 is a deficient number, since it is larger than the sum of its proper divisors (491425154).

666887806 is a wasteful number, since it uses less digits than its factorization.

666887806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361.

The product of its (nonzero) digits is 4644864, while the sum is 55.

The square root of 666887806 is about 25824.1709644279. The cubic root of 666887806 is about 873.6770455590.

The spelling of 666887806 in words is "six hundred sixty-six million, eight hundred eighty-seven thousand, eight hundred six".