28181232 has 120 divisors (see below), whose sum is σ = 83566080. Its totient is φ = 8853120.

The previous prime is 28181203. The next prime is 28181287. The reversal of 28181232 is 23218182.

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

It is a junction number, because it is equal to n+sod(n) for n = 28181196 and 28181205.

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 23 ways as a sum of consecutive naturals, for example, 263323 + ... + 263429.

It is an arithmetic number, because the mean of its divisors is an integer number (696384).

Almost surely, 2^28181232 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 28181232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41783040).

28181232 is an abundant number, since it is smaller than the sum of its proper divisors (55384848).

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

28181232 is a wasteful number, since it uses less digits than its factorization.

28181232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211 (or 202 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 28181232 is about 5308.5998153939. The cubic root of 28181232 is about 304.3126400446.

The spelling of 28181232 in words is "twenty-eight million, one hundred eighty-one thousand, two hundred thirty-two".