28303881 has 4 divisors (see below), whose sum is σ = 37738512. Its totient is φ = 18869252.

The previous prime is 28303879. The next prime is 28303897. The reversal of 28303881 is 18830382.

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 not a de Polignac number, because 28303881 - 2¹ = 28303879 is a prime.

It is a super-2 number, since 2×28303881² = 1602219359324322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28303801) 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, 4717311 + ... + 4717316.

It is an arithmetic number, because the mean of its divisors is an integer number (9434628).

Almost surely, 2^28303881 is an apocalyptic number.

It is an amenable number.

28303881 is a deficient number, since it is larger than the sum of its proper divisors (9434631).

28303881 is an equidigital number, since it uses as much as digits as its factorization.

28303881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9434630.

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 28303881 is about 5320.1391899085. The cubic root of 28303881 is about 304.7534727411.

The spelling of 28303881 in words is "twenty-eight million, three hundred three thousand, eight hundred eighty-one".