28225997 has 4 divisors (see below), whose sum is σ = 28315356. Its totient is φ = 28136640.

The previous prime is 28225993. The next prime is 28226071. The reversal of 28225997 is 79952282.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 988036 + 27237961 = 994^2 + 5219^2 .

It is a cyclic number.

It is not a de Polignac number, because 28225997 - 2² = 28225993 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28225993) 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, 44204 + ... + 44837.

It is an arithmetic number, because the mean of its divisors is an integer number (7078839).

Almost surely, 2^28225997 is an apocalyptic number.

It is an amenable number.

28225997 is a deficient number, since it is larger than the sum of its proper divisors (89359).

28225997 is an equidigital number, since it uses as much as digits as its factorization.

28225997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89358.

The product of its digits is 181440, while the sum is 44.

The square root of 28225997 is about 5312.8144142253. The cubic root of 28225997 is about 304.4736851531.

The spelling of 28225997 in words is "twenty-eight million, two hundred twenty-five thousand, nine hundred ninety-seven".