28015812 has 72 divisors (see below), whose sum is σ = 77837760. Its totient is φ = 8425920.

The previous prime is 28015787. The next prime is 28015837. The reversal of 28015812 is 21851082.

28015812 is a `hidden beast` number, since 2 + 80 + 1 + 581 + 2 = 666.

It is an interprime number because it is at equal distance from previous prime (28015787) and next prime (28015837).

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, 104014 + ... + 104282.

It is an arithmetic number, because the mean of its divisors is an integer number (1081080).

Almost surely, 2^28015812 is an apocalyptic number.

28015812 is a gapful number since it is divisible by the number (22) 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 28015812, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38918880).

28015812 is an abundant number, since it is smaller than the sum of its proper divisors (49821948).

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

28015812 is a wasteful number, since it uses less digits than its factorization.

28015812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 553 (or 548 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The square root of 28015812 is about 5292.9965048165. The cubic root of 28015812 is about 303.7160466036.

Adding to 28015812 its reverse (21851082), we get a palindrome (49866894).

The spelling of 28015812 in words is "twenty-eight million, fifteen thousand, eight hundred twelve".