28504397 has 4 divisors (see below), whose sum is σ = 28585500. Its totient is φ = 28423296.

The previous prime is 28504391. The next prime is 28504403. The reversal of 28504397 is 79340582.

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

It is an interprime number because it is at equal distance from previous prime (28504391) and next prime (28504403).

It can be written as a sum of positive squares in 2 ways, for example, as 20376196 + 8128201 = 4514^2 + 2851^2 .

It is a cyclic number.

It is not a de Polignac number, because 28504397 - 2²⁴ = 11727181 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28504397.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28504391) 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, 40022 + ... + 40727.

It is an arithmetic number, because the mean of its divisors is an integer number (7146375).

Almost surely, 2^28504397 is an apocalyptic number.

It is an amenable number.

28504397 is a deficient number, since it is larger than the sum of its proper divisors (81103).

28504397 is an equidigital number, since it uses as much as digits as its factorization.

28504397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81102.

The product of its (nonzero) digits is 60480, while the sum is 38.

The square root of 28504397 is about 5338.9509269144. The cubic root of 28504397 is about 305.4714450485.

The spelling of 28504397 in words is "twenty-eight million, five hundred four thousand, three hundred ninety-seven".