21613166 has 8 divisors (see below), whose sum is σ = 32667624. Its totient is φ = 10723960.

The previous prime is 21613157. The next prime is 21613177. The reversal of 21613166 is 66131612.

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 pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40985 + ... + 41508.

It is an arithmetic number, because the mean of its divisors is an integer number (4083453).

Almost surely, 2^21613166 is an apocalyptic number.

21613166 is a deficient number, since it is larger than the sum of its proper divisors (11054458).

21613166 is a wasteful number, since it uses less digits than its factorization.

21613166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82626.

The product of its digits is 1296, while the sum is 26.

The square root of 21613166 is about 4648.9962357481. The cubic root of 21613166 is about 278.5519029300.

Adding to 21613166 its reverse (66131612), we get a palindrome (87744778).

The spelling of 21613166 in words is "twenty-one million, six hundred thirteen thousand, one hundred sixty-six".