28243940 has 12 divisors (see below), whose sum is σ = 59312316. Its totient is φ = 11297568.

The previous prime is 28243927. The next prime is 28243951. The reversal of 28243940 is 4934282.

It can be written as a sum of positive squares in 2 ways, for example, as 4351396 + 23892544 = 2086^2 + 4888^2 .

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 28243897 and 28243906.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 706079 + ... + 706118.

It is an arithmetic number, because the mean of its divisors is an integer number (4942693).

Almost surely, 2^28243940 is an apocalyptic number.

28243940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28243940 is an abundant number, since it is smaller than the sum of its proper divisors (31068376).

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

28243940 is a wasteful number, since it uses less digits than its factorization.

28243940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1412206 (or 1412204 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 32.

The square root of 28243940 is about 5314.5027989455. The cubic root of 28243940 is about 304.5381885033.

The spelling of 28243940 in words is "twenty-eight million, two hundred forty-three thousand, nine hundred forty".