28686020 has 48 divisors (see below), whose sum is σ = 66419136. Its totient is φ = 10320000.

The previous prime is 28686011. The next prime is 28686023. The reversal of 28686020 is 2068682.

28686020 = 2² + 3² + ... + 441².

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (28686023) 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, 21575 + ... + 22865.

It is an arithmetic number, because the mean of its divisors is an integer number (1383732).

Almost surely, 2^28686020 is an apocalyptic number.

28686020 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 28686020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33209568).

28686020 is an abundant number, since it is smaller than the sum of its proper divisors (37733116).

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

28686020 is a wasteful number, since it uses less digits than its factorization.

28686020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1412 (or 1410 counting only the distinct ones).

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

The square root of 28686020 is about 5355.9331586569. The cubic root of 28686020 is about 306.1188681964.

It can be divided in two parts, 2868 and 6020, that added together give a palindrome (8888).

The spelling of 28686020 in words is "twenty-eight million, six hundred eighty-six thousand, twenty".