28163840 has 36 divisors (see below), whose sum is σ = 67464264. Its totient is φ = 11265024.

The previous prime is 28163803. The next prime is 28163851. The reversal of 28163840 is 4836182.

It is a super-3 number, since 3×28163840³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 28163797 and 28163806.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9722 + ... + 12281.

Almost surely, 2^28163840 is an apocalyptic number.

28163840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28163840 is an abundant number, since it is smaller than the sum of its proper divisors (39300424).

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

28163840 is an equidigital number, since it uses as much as digits as its factorization.

28163840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22024 (or 22010 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 28163840 is about 5306.9614658484. The cubic root of 28163840 is about 304.2500251504.

The spelling of 28163840 in words is "twenty-eight million, one hundred sixty-three thousand, eight hundred forty".