28105231 has 8 divisors (see below), whose sum is σ = 35040384. Its totient is φ = 21900120.

The previous prime is 28105229. The next prime is 28105243. The reversal of 28105231 is 13250182.

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

It is not a de Polignac number, because 28105231 - 2¹ = 28105229 is a prime.

It is a super-2 number, since 2×28105231² = 1579808019126722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28105291) 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, 182425 + ... + 182578.

It is an arithmetic number, because the mean of its divisors is an integer number (4380048).

Almost surely, 2^28105231 is an apocalyptic number.

28105231 is a deficient number, since it is larger than the sum of its proper divisors (6935153).

28105231 is a wasteful number, since it uses less digits than its factorization.

28105231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 365021.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 28105231 is about 5301.4366920675. The cubic root of 28105231 is about 304.0388303066.

The spelling of 28105231 in words is "twenty-eight million, one hundred five thousand, two hundred thirty-one".