166642665 has 32 divisors (see below), whose sum is σ = 305980416. Its totient is φ = 75864000.

The previous prime is 166642661. The next prime is 166642691. The reversal of 166642665 is 566246661.

It is a happy number.

It is not a de Polignac number, because 166642665 - 2² = 166642661 is a prime.

It is not an unprimeable number, because it can be changed into a prime (166642661) 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 31 ways as a sum of consecutive naturals, for example, 23194 + ... + 29516.

It is an arithmetic number, because the mean of its divisors is an integer number (9561888).

Almost surely, 2^166642665 is an apocalyptic number.

166642665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

166642665 is a deficient number, since it is larger than the sum of its proper divisors (139337751).

166642665 is a wasteful number, since it uses less digits than its factorization.

166642665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6589.

The product of its digits is 311040, while the sum is 42.

The square root of 166642665 is about 12909.0148733356. The cubic root of 166642665 is about 550.2947896285.

The spelling of 166642665 in words is "one hundred sixty-six million, six hundred forty-two thousand, six hundred sixty-five".