21202166 has 8 divisors (see below), whose sum is σ = 32579064. Its totient is φ = 10342480.

The previous prime is 21202141. The next prime is 21202177. The reversal of 21202166 is 66120212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 129200 + ... + 129363.

It is an arithmetic number, because the mean of its divisors is an integer number (4072383).

Almost surely, 2^21202166 is an apocalyptic number.

21202166 is a deficient number, since it is larger than the sum of its proper divisors (11376898).

21202166 is a wasteful number, since it uses less digits than its factorization.

21202166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258606.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 21202166 is about 4604.5809798504. The cubic root of 21202166 is about 276.7749261009.

Adding to 21202166 its reverse (66120212), we get a palindrome (87322378).

The spelling of 21202166 in words is "twenty-one million, two hundred two thousand, one hundred sixty-six".