22521321 has 10 divisors (see below), whose sum is σ = 33643082. Its totient is φ = 15014160.

The previous prime is 22521299. The next prime is 22521329. The reversal of 22521321 is 12312522.

It can be written as a sum of positive squares in only one way, i.e., 20575296 + 1946025 = 4536^2 + 1395^2 .

It is not a de Polignac number, because 22521321 - 2⁷ = 22521193 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 22521294 and 22521303.

It is not an unprimeable number, because it can be changed into a prime (22521329) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 138940 + ... + 139101.

Almost surely, 2^22521321 is an apocalyptic number.

It is an amenable number.

22521321 is a deficient number, since it is larger than the sum of its proper divisors (11121761).

22521321 is an equidigital number, since it uses as much as digits as its factorization.

22521321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 278053 (or 278044 counting only the distinct ones).

The product of its digits is 240, while the sum is 18.

The square root of 22521321 is about 4745.6633888214. The cubic root of 22521321 is about 282.3999530866.

Adding to 22521321 its reverse (12312522), we get a palindrome (34833843).

The spelling of 22521321 in words is "twenty-two million, five hundred twenty-one thousand, three hundred twenty-one".