28396281 has 4 divisors (see below), whose sum is σ = 37861712. Its totient is φ = 18930852.

The previous prime is 28396267. The next prime is 28396289. The reversal of 28396281 is 18269382.

It is a happy number.

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 not a de Polignac number, because 28396281 - 2⁹ = 28395769 is a prime.

It is a super-2 number, since 2×28396281² = 1612697549261922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28396289) 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, 4732711 + ... + 4732716.

It is an arithmetic number, because the mean of its divisors is an integer number (9465428).

Almost surely, 2^28396281 is an apocalyptic number.

It is an amenable number.

28396281 is a deficient number, since it is larger than the sum of its proper divisors (9465431).

28396281 is an equidigital number, since it uses as much as digits as its factorization.

28396281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9465430.

The product of its digits is 41472, while the sum is 39.

The square root of 28396281 is about 5328.8160974085. The cubic root of 28396281 is about 305.0847421967.

The spelling of 28396281 in words is "twenty-eight million, three hundred ninety-six thousand, two hundred eighty-one".