28028493 has 6 divisors (see below), whose sum is σ = 40485614. Its totient is φ = 18685656.

The previous prime is 28028491. The next prime is 28028501. The reversal of 28028493 is 39482082.

It can be written as a sum of positive squares in only one way, i.e., 17413929 + 10614564 = 4173^2 + 3258^2 .

It is not a de Polignac number, because 28028493 - 2¹ = 28028491 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 (28028491) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1557130 + ... + 1557147.

Almost surely, 2^28028493 is an apocalyptic number.

It is an amenable number.

28028493 is a deficient number, since it is larger than the sum of its proper divisors (12457121).

28028493 is a wasteful number, since it uses less digits than its factorization.

28028493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3114283 (or 3114280 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 28028493 is about 5294.1942729749. The cubic root of 28028493 is about 303.7618640898.

The spelling of 28028493 in words is "twenty-eight million, twenty-eight thousand, four hundred ninety-three".