28270399 has 4 divisors (see below), whose sum is σ = 28301760. Its totient is φ = 28239040.

The previous prime is 28270391. The next prime is 28270421. The reversal of 28270399 is 99307282.

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

It is a cyclic number.

It is not a de Polignac number, because 28270399 - 2³ = 28270391 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 (28270391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14287 + ... + 16144.

It is an arithmetic number, because the mean of its divisors is an integer number (7075440).

Almost surely, 2^28270399 is an apocalyptic number.

28270399 is a deficient number, since it is larger than the sum of its proper divisors (31361).

28270399 is an equidigital number, since it uses as much as digits as its factorization.

28270399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31360.

The product of its (nonzero) digits is 54432, while the sum is 40.

The square root of 28270399 is about 5316.9915365740. The cubic root of 28270399 is about 304.6332562247.

The spelling of 28270399 in words is "twenty-eight million, two hundred seventy thousand, three hundred ninety-nine".