21822243 has 4 divisors (see below), whose sum is σ = 29096328. Its totient is φ = 14548160.

The previous prime is 21822223. The next prime is 21822287. The reversal of 21822243 is 34222812.

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 21822243 - 2¹⁷ = 21691171 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21822223) 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, 3637038 + ... + 3637043.

It is an arithmetic number, because the mean of its divisors is an integer number (7274082).

Almost surely, 2^21822243 is an apocalyptic number.

21822243 is a deficient number, since it is larger than the sum of its proper divisors (7274085).

21822243 is an equidigital number, since it uses as much as digits as its factorization.

21822243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7274084.

The product of its digits is 1536, while the sum is 24.

The square root of 21822243 is about 4671.4283682831. The cubic root of 21822243 is about 279.4472214927.

The spelling of 21822243 in words is "twenty-one million, eight hundred twenty-two thousand, two hundred forty-three".