21669166 has 8 divisors (see below), whose sum is σ = 33054840. Its totient is φ = 10650888.

The previous prime is 21669157. The next prime is 21669173. The reversal of 21669166 is 66196612.

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, 91701 + ... + 91936.

It is an arithmetic number, because the mean of its divisors is an integer number (4131855).

Almost surely, 2^21669166 is an apocalyptic number.

21669166 is a deficient number, since it is larger than the sum of its proper divisors (11385674).

21669166 is a wasteful number, since it uses less digits than its factorization.

21669166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183698.

The product of its digits is 23328, while the sum is 37.

The square root of 21669166 is about 4655.0151449807. The cubic root of 21669166 is about 278.7922726750.

The spelling of 21669166 in words is "twenty-one million, six hundred sixty-nine thousand, one hundred sixty-six".