28222225 has 6 divisors (see below), whose sum is σ = 34995590. Its totient is φ = 22577760.

The previous prime is 28222223. The next prime is 28222253. The reversal of 28222225 is 52222282.

It can be written as a sum of positive squares in 3 ways, for example, as 5602689 + 22619536 = 2367^2 + 4756^2 .

It is not a de Polignac number, because 28222225 - 2¹ = 28222223 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25), and also a Moran number because the ratio is a prime number: 1128889 = 28222225 / (2 + 8 + 2 + 2 + 2 + 2 + 2 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 28222225.

It is not an unprimeable number, because it can be changed into a prime (28222223) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 564420 + ... + 564469.

Almost surely, 2^28222225 is an apocalyptic number.

28222225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28222225 is a deficient number, since it is larger than the sum of its proper divisors (6773365).

28222225 is a wasteful number, since it uses less digits than its factorization.

28222225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1128899 (or 1128894 counting only the distinct ones).

The product of its digits is 2560, while the sum is 25.

The square root of 28222225 is about 5312.4594116097. The cubic root of 28222225 is about 304.4601217006.

The spelling of 28222225 in words is "twenty-eight million, two hundred twenty-two thousand, two hundred twenty-five".