28198281 has 8 divisors (see below), whose sum is σ = 37689120. Its totient is φ = 18753152.

The previous prime is 28198273. The next prime is 28198301. The reversal of 28198281 is 18289182.

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 28198281 - 2³ = 28198273 is a prime.

It is a super-2 number, since 2×28198281² = 1590286102709922, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28198211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9960 + ... + 12473.

It is an arithmetic number, because the mean of its divisors is an integer number (4711140).

Almost surely, 2^28198281 is an apocalyptic number.

It is an amenable number.

28198281 is a deficient number, since it is larger than the sum of its proper divisors (9490839).

28198281 is a wasteful number, since it uses less digits than its factorization.

28198281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22855.

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

The square root of 28198281 is about 5310.2053632604. The cubic root of 28198281 is about 304.3739950663.

Subtracting from 28198281 its reverse (18289182), we obtain a palindrome (9909099).

The spelling of 28198281 in words is "twenty-eight million, one hundred ninety-eight thousand, two hundred eighty-one".