21968303 has 4 divisors (see below), whose sum is σ = 25106640. Its totient is φ = 18829968.

The previous prime is 21968293. The next prime is 21968321. The reversal of 21968303 is 30386912.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21968303 - 2⁶ = 21968239 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21968303.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21968363) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1569158 + ... + 1569171.

It is an arithmetic number, because the mean of its divisors is an integer number (6276660).

Almost surely, 2^21968303 is an apocalyptic number.

21968303 is a deficient number, since it is larger than the sum of its proper divisors (3138337).

21968303 is an equidigital number, since it uses as much as digits as its factorization.

21968303 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3138336.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 21968303 is about 4687.0356303318. The cubic root of 21968303 is about 280.0692983239.

The spelling of 21968303 in words is "twenty-one million, nine hundred sixty-eight thousand, three hundred three".