21866606 has 32 divisors (see below), whose sum is σ = 36495360. Its totient is φ = 9779616.

The previous prime is 21866597. The next prime is 21866671. The reversal of 21866606 is 60666812.

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 15 ways as a sum of consecutive naturals, for example, 110900 + ... + 111096.

It is an arithmetic number, because the mean of its divisors is an integer number (1140480).

Almost surely, 2^21866606 is an apocalyptic number.

21866606 is a deficient number, since it is larger than the sum of its proper divisors (14628754).

21866606 is a wasteful number, since it uses less digits than its factorization.

21866606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 368.

The product of its (nonzero) digits is 20736, while the sum is 35.

The square root of 21866606 is about 4676.1742910204. The cubic root of 21866606 is about 279.6364584677.

The spelling of 21866606 in words is "twenty-one million, eight hundred sixty-six thousand, six hundred six".