28140520 has 64 divisors (see below), whose sum is σ = 67852800. Its totient is φ = 10471680.

The previous prime is 28140517. The next prime is 28140521. The reversal of 28140520 is 2504182.

It is a junction number, because it is equal to n+sod(n) for n = 28140491 and 28140500.

It is not an unprimeable number, because it can be changed into a prime (28140521) 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, 46057 + ... + 46663.

It is an arithmetic number, because the mean of its divisors is an integer number (1060200).

Almost surely, 2^28140520 is an apocalyptic number.

28140520 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 28140520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33926400).

28140520 is an abundant number, since it is smaller than the sum of its proper divisors (39712280).

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

28140520 is a wasteful number, since it uses less digits than its factorization.

28140520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 698 (or 694 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 28140520 is about 5304.7638967253. The cubic root of 28140520 is about 304.1660277295.

The spelling of 28140520 in words is "twenty-eight million, one hundred forty thousand, five hundred twenty".