28543431 has 16 divisors (see below), whose sum is σ = 44384000. Its totient is φ = 16309944.

The previous prime is 28543399. The next prime is 28543439. The reversal of 28543431 is 13434582.

It is not a de Polignac number, because 28543431 - 2⁵ = 28543399 is a prime.

It is a super-2 number, since 2×28543431² = 1629454906503522, 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 (28543439) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12841 + ... + 14898.

It is an arithmetic number, because the mean of its divisors is an integer number (2774000).

Almost surely, 2^28543431 is an apocalyptic number.

28543431 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

28543431 is a deficient number, since it is larger than the sum of its proper divisors (15840569).

28543431 is an equidigital number, since it uses as much as digits as its factorization.

28543431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27763 (or 27749 counting only the distinct ones).

The product of its digits is 11520, while the sum is 30.

The square root of 28543431 is about 5342.6052633523. The cubic root of 28543431 is about 305.6108192617.

The spelling of 28543431 in words is "twenty-eight million, five hundred forty-three thousand, four hundred thirty-one".