28143936 has 140 divisors (see below), whose sum is σ = 85747860. Its totient is φ = 9123840.

The previous prime is 28143911. The next prime is 28143943. The reversal of 28143936 is 63934182.

It can be written as a sum of positive squares in 2 ways, for example, as 2742336 + 25401600 = 1656^2 + 5040^2 .

It is a super-2 number, since 2×28143936² = 1584162267144192, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 28143936.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 316180 + ... + 316268.

Almost surely, 2^28143936 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28143936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42873930).

28143936 is an abundant number, since it is smaller than the sum of its proper divisors (57603924).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28143936 is an equidigital number, since it uses as much as digits as its factorization.

28143936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174 (or 155 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 28143936 is about 5305.0858616991. The cubic root of 28143936 is about 304.1783348832.

The spelling of 28143936 in words is "twenty-eight million, one hundred forty-three thousand, nine hundred thirty-six".