166635663 has 4 divisors (see below), whose sum is σ = 222180888. Its totient is φ = 111090440.

The previous prime is 166635641. The next prime is 166635673. The reversal of 166635663 is 366536661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 366536661 = 3 ⋅122178887.

It is a cyclic number.

It is not a de Polignac number, because 166635663 - 2⁵ = 166635631 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166635613) 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, 27772608 + ... + 27772613.

It is an arithmetic number, because the mean of its divisors is an integer number (55545222).

Almost surely, 2^166635663 is an apocalyptic number.

166635663 is a deficient number, since it is larger than the sum of its proper divisors (55545225).

166635663 is an equidigital number, since it uses as much as digits as its factorization.

166635663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55545224.

The product of its digits is 349920, while the sum is 42.

The square root of 166635663 is about 12908.7436646639. The cubic root of 166635663 is about 550.2870820824.

The spelling of 166635663 in words is "one hundred sixty-six million, six hundred thirty-five thousand, six hundred sixty-three".