21222663 has 16 divisors (see below), whose sum is σ = 35279616. Its totient is φ = 11024640.

The previous prime is 21222653. The next prime is 21222671. The reversal of 21222663 is 36622212.

It is not a de Polignac number, because 21222663 - 2¹⁸ = 20960519 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222653) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45706 + ... + 46167.

It is an arithmetic number, because the mean of its divisors is an integer number (2204976).

Almost surely, 2^21222663 is an apocalyptic number.

21222663 is a deficient number, since it is larger than the sum of its proper divisors (14056953).

21222663 is a wasteful number, since it uses less digits than its factorization.

21222663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91894.

The product of its digits is 1728, while the sum is 24.

The square root of 21222663 is about 4606.8061604543. The cubic root of 21222663 is about 276.8640872510.

Adding to 21222663 its reverse (36622212), we get a palindrome (57844875).

The spelling of 21222663 in words is "twenty-one million, two hundred twenty-two thousand, six hundred sixty-three".