28297205 has 4 divisors (see below), whose sum is σ = 33956652. Its totient is φ = 22637760.

The previous prime is 28297201. The next prime is 28297219. The reversal of 28297205 is 50279282.

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 15062161 + 13235044 = 3881^2 + 3638^2 .

It is not a de Polignac number, because 28297205 - 2² = 28297201 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 (28297201) 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, 2829716 + ... + 2829725.

It is an arithmetic number, because the mean of its divisors is an integer number (8489163).

Almost surely, 2^28297205 is an apocalyptic number.

It is an amenable number.

28297205 is a deficient number, since it is larger than the sum of its proper divisors (5659447).

28297205 is an equidigital number, since it uses as much as digits as its factorization.

28297205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5659446.

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 28297205 is about 5319.5117257132. The cubic root of 28297205 is about 304.7295102538.

The spelling of 28297205 in words is "twenty-eight million, two hundred ninety-seven thousand, two hundred five".