28181328 has 40 divisors (see below), whose sum is σ = 83203008. Its totient is φ = 8051712.

The previous prime is 28181317. The next prime is 28181347. The reversal of 28181328 is 82318182.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41601 + ... + 42272.

Almost surely, 2^28181328 is an apocalyptic number.

28181328 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

28181328 is an abundant number, since it is smaller than the sum of its proper divisors (55021680).

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

28181328 is a wasteful number, since it uses less digits than its factorization.

28181328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83891 (or 83885 counting only the distinct ones).

The product of its digits is 6144, while the sum is 33.

The square root of 28181328 is about 5308.6088573185. The cubic root of 28181328 is about 304.3129855935.

The spelling of 28181328 in words is "twenty-eight million, one hundred eighty-one thousand, three hundred twenty-eight".