666166101 has 4 divisors (see below), whose sum is σ = 888221472. Its totient is φ = 444110732.

The previous prime is 666166069. The next prime is 666166121. The reversal of 666166101 is 101661666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 666166101 - 2⁵ = 666166069 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666166121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111027681 + ... + 111027686.

It is an arithmetic number, because the mean of its divisors is an integer number (222055368).

Almost surely, 2^666166101 is an apocalyptic number.

It is an amenable number.

666166101 is a deficient number, since it is larger than the sum of its proper divisors (222055371).

666166101 is a wasteful number, since it uses less digits than its factorization.

666166101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222055370.

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 666166101 is about 25810.1937420082. The cubic root of 666166101 is about 873.3617677972.

The spelling of 666166101 in words is "six hundred sixty-six million, one hundred sixty-six thousand, one hundred one".