28516780 has 48 divisors (see below), whose sum is σ = 63866880. Its totient is φ = 10670528.

The previous prime is 28516759. The next prime is 28516781. The reversal of 28516780 is 8761582.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (28516781) 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, 20961 + ... + 22279.

It is an arithmetic number, because the mean of its divisors is an integer number (1330560).

Almost surely, 2^28516780 is an apocalyptic number.

28516780 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 28516780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31933440).

28516780 is an abundant number, since it is smaller than the sum of its proper divisors (35350100).

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

28516780 is a wasteful number, since it uses less digits than its factorization.

28516780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1398 (or 1396 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 37.

The square root of 28516780 is about 5340.1104857484. The cubic root of 28516780 is about 305.5156733744.

The spelling of 28516780 in words is "twenty-eight million, five hundred sixteen thousand, seven hundred eighty".