28431831 has 8 divisors (see below), whose sum is σ = 38080000. Its totient is φ = 18869112.

The previous prime is 28431829. The next prime is 28431833. The reversal of 28431831 is 13813482.

It is an interprime number because it is at equal distance from previous prime (28431829) and next prime (28431833).

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

It is not a de Polignac number, because 28431831 - 2¹ = 28431829 is a prime.

It is a super-2 number, since 2×28431831² = 1616738028025122, 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 (28431833) 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, 20581 + ... + 21918.

It is an arithmetic number, because the mean of its divisors is an integer number (4760000).

Almost surely, 2^28431831 is an apocalyptic number.

28431831 is a deficient number, since it is larger than the sum of its proper divisors (9648169).

28431831 is a wasteful number, since it uses less digits than its factorization.

28431831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42725.

The product of its digits is 4608, while the sum is 30.

The square root of 28431831 is about 5332.1506917941. The cubic root of 28431831 is about 305.2120034592.

The spelling of 28431831 in words is "twenty-eight million, four hundred thirty-one thousand, eight hundred thirty-one".