21322231 has 4 divisors (see below), whose sum is σ = 24368272. Its totient is φ = 18276192.

The previous prime is 21322229. The next prime is 21322241. The reversal of 21322231 is 13222312.

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 21322231 - 2¹ = 21322229 is a prime.

It is a super-2 number, since 2×21322231² = 909275069634722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21322201) 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, 1523010 + ... + 1523023.

It is an arithmetic number, because the mean of its divisors is an integer number (6092068).

Almost surely, 2^21322231 is an apocalyptic number.

21322231 is a deficient number, since it is larger than the sum of its proper divisors (3046041).

21322231 is an equidigital number, since it uses as much as digits as its factorization.

21322231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3046040.

The product of its digits is 144, while the sum is 16.

The square root of 21322231 is about 4617.6001342689. The cubic root of 21322231 is about 277.2963893417.

Adding to 21322231 its reverse (13222312), we get a palindrome (34544543).

It can be divided in two parts, 2 and 1322231, that multiplied together give a palindrome (2644462).

The spelling of 21322231 in words is "twenty-one million, three hundred twenty-two thousand, two hundred thirty-one".