28211297 has 4 divisors (see below), whose sum is σ = 28290240. Its totient is φ = 28132356.

The previous prime is 28211291. The next prime is 28211303. The reversal of 28211297 is 79211282.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (28211291) and next prime (28211303).

It is a cyclic number.

It is not a de Polignac number, because 28211297 - 2²⁰ = 27162721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28211291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38933 + ... + 39650.

It is an arithmetic number, because the mean of its divisors is an integer number (7072560).

Almost surely, 2^28211297 is an apocalyptic number.

It is an amenable number.

28211297 is a deficient number, since it is larger than the sum of its proper divisors (78943).

28211297 is an equidigital number, since it uses as much as digits as its factorization.

28211297 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78942.

The product of its digits is 4032, while the sum is 32.

The square root of 28211297 is about 5311.4307865207. The cubic root of 28211297 is about 304.4208196997.

The spelling of 28211297 in words is "twenty-eight million, two hundred eleven thousand, two hundred ninety-seven".