225721224 has 24 divisors (see below), whose sum is σ = 611328510. Its totient is φ = 75240384.

The previous prime is 225721219. The next prime is 225721247. The reversal of 225721224 is 422127522.

225721224 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 181764324 + 43956900 = 13482^2 + 6630^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1567437 + ... + 1567580.

Almost surely, 2^225721224 is an apocalyptic number.

225721224 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

225721224 is an abundant number, since it is smaller than the sum of its proper divisors (385607286).

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

225721224 is a wasteful number, since it uses less digits than its factorization.

225721224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3135029 (or 3135022 counting only the distinct ones).

The product of its digits is 4480, while the sum is 27.

The square root of 225721224 is about 15024.0215654797. The cubic root of 225721224 is about 608.8693775358.

Adding to 225721224 its reverse (422127522), we get a palindrome (647848746).

The spelling of 225721224 in words is "two hundred twenty-five million, seven hundred twenty-one thousand, two hundred twenty-four".