21968245 has 8 divisors (see below), whose sum is σ = 28389816. Its totient is φ = 16222656.

The previous prime is 21968239. The next prime is 21968257. The reversal of 21968245 is 54286912.

It can be written as a sum of positive squares in 4 ways, for example, as 224676 + 21743569 = 474^2 + 4663^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21968245 - 2⁷ = 21968117 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 168922 + ... + 169051.

It is an arithmetic number, because the mean of its divisors is an integer number (3548727).

Almost surely, 2^21968245 is an apocalyptic number.

It is an amenable number.

21968245 is a deficient number, since it is larger than the sum of its proper divisors (6421571).

21968245 is a wasteful number, since it uses less digits than its factorization.

21968245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 337991.

The product of its digits is 34560, while the sum is 37.

The square root of 21968245 is about 4687.0294430481. The cubic root of 21968245 is about 280.0690518470.

The spelling of 21968245 in words is "twenty-one million, nine hundred sixty-eight thousand, two hundred forty-five".