28015312 has 30 divisors (see below), whose sum is σ = 58614738. Its totient is φ = 12894912.

The previous prime is 28015297. The next prime is 28015319. The reversal of 28015312 is 21351082.

It can be written as a sum of positive squares in only one way, i.e., 19395216 + 8620096 = 4404^2 + 2936^2 .

It is a hoax number, since the sum of its digits (22) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28015319) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 76153 + ... + 76519.

Almost surely, 2^28015312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28015312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29307369).

28015312 is an abundant number, since it is smaller than the sum of its proper divisors (30599426).

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

28015312 is an equidigital number, since it uses as much as digits as its factorization.

28015312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 755 (or 382 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 28015312 is about 5292.9492723811. The cubic root of 28015312 is about 303.7142397796.

Adding to 28015312 its reverse (21351082), we get a palindrome (49366394).

The spelling of 28015312 in words is "twenty-eight million, fifteen thousand, three hundred twelve".