28686140 has 72 divisors (see below), whose sum is σ = 73237920. Its totient is φ = 9243648.

The previous prime is 28686127. The next prime is 28686167. The reversal of 28686140 is 4168682.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 28686140.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 40106 + ... + 40814.

Almost surely, 2^28686140 is an apocalyptic number.

28686140 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 28686140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36618960).

28686140 is an abundant number, since it is smaller than the sum of its proper divisors (44551780).

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

28686140 is a wasteful number, since it uses less digits than its factorization.

28686140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 759 (or 740 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 35.

The square root of 28686140 is about 5355.9443611748. The cubic root of 28686140 is about 306.1192950502.

The spelling of 28686140 in words is "twenty-eight million, six hundred eighty-six thousand, one hundred forty".