28120393 has 4 divisors (see below), whose sum is σ = 32137600. Its totient is φ = 24103188.

The previous prime is 28120387. The next prime is 28120423. The reversal of 28120393 is 39302182.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28120393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28120373) 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, 2008593 + ... + 2008606.

It is an arithmetic number, because the mean of its divisors is an integer number (8034400).

Almost surely, 2^28120393 is an apocalyptic number.

It is an amenable number.

28120393 is a deficient number, since it is larger than the sum of its proper divisors (4017207).

28120393 is an equidigital number, since it uses as much as digits as its factorization.

28120393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4017206.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 28120393 is about 5302.8664889850. The cubic root of 28120393 is about 304.0934940100.

The spelling of 28120393 in words is "twenty-eight million, one hundred twenty thousand, three hundred ninety-three".