21326668 has 24 divisors (see below), whose sum is σ = 41000400. Its totient is φ = 9625920.

The previous prime is 21326663. The next prime is 21326699. The reversal of 21326668 is 86662312.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21326663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4930 + ... + 8182.

It is an arithmetic number, because the mean of its divisors is an integer number (1708350).

Almost surely, 2^21326668 is an apocalyptic number.

It is an amenable number.

21326668 is a deficient number, since it is larger than the sum of its proper divisors (19673732).

21326668 is a wasteful number, since it uses less digits than its factorization.

21326668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3417 (or 3415 counting only the distinct ones).

The product of its digits is 20736, while the sum is 34.

The square root of 21326668 is about 4618.0805536500. The cubic root of 21326668 is about 277.3156224565.

The spelling of 21326668 in words is "twenty-one million, three hundred twenty-six thousand, six hundred sixty-eight".