21222253 has 4 divisors (see below), whose sum is σ = 22854748. Its totient is φ = 19589760.

The previous prime is 21222251. The next prime is 21222269. The reversal of 21222253 is 35222212.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1747684 + 19474569 = 1322^2 + 4413^2 .

It is a cyclic number.

It is not a de Polignac number, because 21222253 - 2¹ = 21222251 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 21222253.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222251) 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, 816228 + ... + 816253.

It is an arithmetic number, because the mean of its divisors is an integer number (5713687).

Almost surely, 2^21222253 is an apocalyptic number.

It is an amenable number.

21222253 is a deficient number, since it is larger than the sum of its proper divisors (1632495).

21222253 is a wasteful number, since it uses less digits than its factorization.

21222253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1632494.

The product of its digits is 480, while the sum is 19.

The square root of 21222253 is about 4606.7616608633. The cubic root of 21222253 is about 276.8623043298.

Adding to 21222253 its reverse (35222212), we get a palindrome (56444465).

The spelling of 21222253 in words is "twenty-one million, two hundred twenty-two thousand, two hundred fifty-three".