22721172 has 12 divisors (see below), whose sum is σ = 53016096. Its totient is φ = 7573720.

The previous prime is 22721161. The next prime is 22721191. The reversal of 22721172 is 27112722.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 946704 + ... + 946727.

It is an arithmetic number, because the mean of its divisors is an integer number (4418008).

Almost surely, 2^22721172 is an apocalyptic number.

It is an amenable number.

22721172 is an abundant number, since it is smaller than the sum of its proper divisors (30294924).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

22721172 is a wasteful number, since it uses less digits than its factorization.

22721172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1893438 (or 1893436 counting only the distinct ones).

The product of its digits is 784, while the sum is 24.

The square root of 22721172 is about 4766.6730536088. The cubic root of 22721172 is about 283.2328200177.

Adding to 22721172 its reverse (27112722), we get a palindrome (49833894).

The spelling of 22721172 in words is "twenty-two million, seven hundred twenty-one thousand, one hundred seventy-two".