28740 has 24 divisors (see below), whose sum is σ = 80640. Its totient is φ = 7648.

The previous prime is 28729. The next prime is 28751. The reversal of 28740 is 4782.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (28729) and next prime (28751).

It is an unprimeable number.

28740 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 180 + ... + 299.

It is an arithmetic number, because the mean of its divisors is an integer number (3360).

2²⁸⁷⁴⁰ is an apocalyptic number.

28740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28740 is an abundant number, since it is smaller than the sum of its proper divisors (51900).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40320).

28740 is a wasteful number, since it uses less digits than its factorization.

28740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 491 (or 489 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 21.

The square root of 28740 is about 169.5287586222. The cubic root of 28740 is about 30.6310761233.

The spelling of 28740 in words is "twenty-eight thousand, seven hundred forty".