28512831 has 8 divisors (see below), whose sum is σ = 38041984. Its totient is φ = 18996120.

The previous prime is 28512817. The next prime is 28512833. The reversal of 28512831 is 13821582.

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

It is not a de Polignac number, because 28512831 - 2⁷ = 28512703 is a prime.

It is a super-2 number, since 2×28512831² = 1625963063269122, 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 (28512833) 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, 6366 + ... + 9876.

It is an arithmetic number, because the mean of its divisors is an integer number (4755248).

Almost surely, 2^28512831 is an apocalyptic number.

28512831 is a deficient number, since it is larger than the sum of its proper divisors (9529153).

28512831 is a wasteful number, since it uses less digits than its factorization.

28512831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6221.

The product of its digits is 3840, while the sum is 30.

The square root of 28512831 is about 5339.7407240427. The cubic root of 28512831 is about 305.5015701331.

The spelling of 28512831 in words is "twenty-eight million, five hundred twelve thousand, eight hundred thirty-one".