22744721 has 4 divisors (see below), whose sum is σ = 23273712. Its totient is φ = 22215732.

The previous prime is 22744717. The next prime is 22744741. The reversal of 22744721 is 12744722.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12744722 = 2 ⋅6372361.

It is a cyclic number.

It is not a de Polignac number, because 22744721 - 2² = 22744717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22744741) 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, 264431 + ... + 264516.

It is an arithmetic number, because the mean of its divisors is an integer number (5818428).

Almost surely, 2^22744721 is an apocalyptic number.

It is an amenable number.

22744721 is a deficient number, since it is larger than the sum of its proper divisors (528991).

22744721 is an equidigital number, since it uses as much as digits as its factorization.

22744721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528990.

The product of its digits is 6272, while the sum is 29.

The square root of 22744721 is about 4769.1425854130. The cubic root of 22744721 is about 283.3306369601.

Subtracting from 22744721 its reverse (12744722), we obtain a palindrome (9999999).

The spelling of 22744721 in words is "twenty-two million, seven hundred forty-four thousand, seven hundred twenty-one".