21253222 has 4 divisors (see below), whose sum is σ = 31879836. Its totient is φ = 10626610.

The previous prime is 21253217. The next prime is 21253237. The reversal of 21253222 is 22235212.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21253222.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5313304 + ... + 5313307.

It is an arithmetic number, because the mean of its divisors is an integer number (7969959).

Almost surely, 2^21253222 is an apocalyptic number.

21253222 is a deficient number, since it is larger than the sum of its proper divisors (10626614).

21253222 is a wasteful number, since it uses less digits than its factorization.

21253222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10626613.

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

The square root of 21253222 is about 4610.1216903678. The cubic root of 21253222 is about 276.9969111725.

Adding to 21253222 its reverse (22235212), we get a palindrome (43488434).

The spelling of 21253222 in words is "twenty-one million, two hundred fifty-three thousand, two hundred twenty-two".