21622866 has 16 divisors (see below), whose sum is σ = 43434144. Its totient is φ = 7176224.

The previous prime is 21622859. The next prime is 21622871. The reversal of 21622866 is 66822612.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6336 + ... + 9131.

It is an arithmetic number, because the mean of its divisors is an integer number (2714634).

Almost surely, 2^21622866 is an apocalyptic number.

21622866 is an abundant number, since it is smaller than the sum of its proper divisors (21811278).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21622866 is a wasteful number, since it uses less digits than its factorization.

21622866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15705.

The product of its digits is 13824, while the sum is 33.

The square root of 21622866 is about 4650.0393546722. The cubic root of 21622866 is about 278.5935681099.

The spelling of 21622866 in words is "twenty-one million, six hundred twenty-two thousand, eight hundred sixty-six".