28819281 has 8 divisors (see below), whose sum is σ = 38495520. Its totient is φ = 19177952.

The previous prime is 28819261. The next prime is 28819283. The reversal of 28819281 is 18291882.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28819281 - 2⁵ = 28819249 is a prime.

It is a super-2 number, since 2×28819281² = 1661101914713922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28819283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6735 + ... + 10148.

It is an arithmetic number, because the mean of its divisors is an integer number (4811940).

Almost surely, 2^28819281 is an apocalyptic number.

It is an amenable number.

28819281 is a deficient number, since it is larger than the sum of its proper divisors (9676239).

28819281 is a wasteful number, since it uses less digits than its factorization.

28819281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17455.

The product of its digits is 18432, while the sum is 39.

The square root of 28819281 is about 5368.3592465482. The cubic root of 28819281 is about 306.5921614582.

The spelling of 28819281 in words is "twenty-eight million, eight hundred nineteen thousand, two hundred eighty-one".