28404253 has 4 divisors (see below), whose sum is σ = 29383740. Its totient is φ = 27424768.

The previous prime is 28404251. The next prime is 28404269. The reversal of 28404253 is 35240482.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 35240482 = 2 ⋅17620241.

It can be written as a sum of positive squares in 2 ways, for example, as 7991929 + 20412324 = 2827^2 + 4518^2 .

It is a cyclic number.

It is not a de Polignac number, because 28404253 - 2¹ = 28404251 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 (28404251) 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, 489700 + ... + 489757.

It is an arithmetic number, because the mean of its divisors is an integer number (7345935).

Almost surely, 2^28404253 is an apocalyptic number.

It is an amenable number.

28404253 is a deficient number, since it is larger than the sum of its proper divisors (979487).

28404253 is an equidigital number, since it uses as much as digits as its factorization.

28404253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 979486.

The product of its (nonzero) digits is 7680, while the sum is 28.

The square root of 28404253 is about 5329.5640534663. The cubic root of 28404253 is about 305.1132894562.

The spelling of 28404253 in words is "twenty-eight million, four hundred four thousand, two hundred fifty-three".