21868766 has 8 divisors (see below), whose sum is σ = 34732800. Its totient is φ = 10291168.

The previous prime is 21868751. The next prime is 21868787. The reversal of 21868766 is 66786812.

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, 321566 + ... + 321633.

It is an arithmetic number, because the mean of its divisors is an integer number (4341600).

Almost surely, 2^21868766 is an apocalyptic number.

21868766 is a deficient number, since it is larger than the sum of its proper divisors (12864034).

21868766 is a wasteful number, since it uses less digits than its factorization.

21868766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643218.

The product of its digits is 193536, while the sum is 44.

The square root of 21868766 is about 4676.4052433466. The cubic root of 21868766 is about 279.6456657320.

The spelling of 21868766 in words is "twenty-one million, eight hundred sixty-eight thousand, seven hundred sixty-six".