666121666 has 32 divisors (see below), whose sum is σ = 1157131008. Its totient is φ = 281702400.

The previous prime is 666121633. The next prime is 666121669.

666121666 is nontrivially palindromic in base 10.

666121666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (666121669) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 415266 + ... + 416866.

It is an arithmetic number, because the mean of its divisors is an integer number (36160344).

Almost surely, 2^666121666 is an apocalyptic number.

666121666 is a deficient number, since it is larger than the sum of its proper divisors (491009342).

666121666 is a wasteful number, since it uses less digits than its factorization.

666121666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1986.

The product of its digits is 93312, while the sum is 40.

The square root of 666121666 is about 25809.3329243512. The cubic root of 666121666 is about 873.3423488700.

The spelling of 666121666 in words is "six hundred sixty-six million, one hundred twenty-one thousand, six hundred sixty-six".