28165831 has 4 divisors (see below), whose sum is σ = 28765152. Its totient is φ = 27566512.

The previous prime is 28165799. The next prime is 28165861. The reversal of 28165831 is 13856182.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13856182 = 2 ⋅6928091.

It is a cyclic number.

It is not a de Polignac number, because 28165831 - 2⁵ = 28165799 is a prime.

It is a super-2 number, since 2×28165831² = 1586628071841122, 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 (28165861) 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, 299590 + ... + 299683.

It is an arithmetic number, because the mean of its divisors is an integer number (7191288).

Almost surely, 2^28165831 is an apocalyptic number.

28165831 is a deficient number, since it is larger than the sum of its proper divisors (599321).

28165831 is an equidigital number, since it uses as much as digits as its factorization.

28165831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 599320.

The product of its digits is 11520, while the sum is 34.

The square root of 28165831 is about 5307.1490463336. The cubic root of 28165831 is about 304.2571944797.

The spelling of 28165831 in words is "twenty-eight million, one hundred sixty-five thousand, eight hundred thirty-one".