28239040 has 112 divisors (see below), whose sum is σ = 74066400. Its totient is φ = 10207232.

The previous prime is 28239031. The next prime is 28239049. The reversal of 28239040 is 4093282.

It is an interprime number because it is at equal distance from previous prime (28239031) and next prime (28239049).

It is not an unprimeable number, because it can be changed into a prime (28239049) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 157671 + ... + 157849.

Almost surely, 2^28239040 is an apocalyptic number.

28239040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28239040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37033200).

28239040 is an abundant number, since it is smaller than the sum of its proper divisors (45827360).

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

28239040 is a wasteful number, since it uses less digits than its factorization.

28239040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242 (or 232 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 28239040 is about 5314.0417762754. The cubic root of 28239040 is about 304.5205761893.

The spelling of 28239040 in words is "twenty-eight million, two hundred thirty-nine thousand, forty".