21968266 has 8 divisors (see below), whose sum is σ = 34385184. Its totient is φ = 10506540.

The previous prime is 21968263. The next prime is 21968279. The reversal of 21968266 is 66286912.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21968266² = 965209422093512, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21968263) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 238740 + ... + 238831.

It is an arithmetic number, because the mean of its divisors is an integer number (4298148).

Almost surely, 2^21968266 is an apocalyptic number.

21968266 is a deficient number, since it is larger than the sum of its proper divisors (12416918).

21968266 is a wasteful number, since it uses less digits than its factorization.

21968266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 477596.

The product of its digits is 62208, while the sum is 40.

The square root of 21968266 is about 4687.0316832725. The cubic root of 21968266 is about 280.0691410887.

The spelling of 21968266 in words is "twenty-one million, nine hundred sixty-eight thousand, two hundred sixty-six".