28081312 has 36 divisors (see below), whose sum is σ = 64314810. Its totient is φ = 12034176.

The previous prime is 28081253. The next prime is 28081337. The reversal of 28081312 is 21318082.

It can be written as a sum of positive squares in only one way, i.e., 24561936 + 3519376 = 4956^2 + 1876^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7387 + ... + 10522.

Almost surely, 2^28081312 is an apocalyptic number.

It is an amenable number.

28081312 is an abundant number, since it is smaller than the sum of its proper divisors (36233498).

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

28081312 is a wasteful number, since it uses less digits than its factorization.

28081312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17933 (or 17918 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 28081312 is about 5299.1803139731. The cubic root of 28081312 is about 303.9525549225.

Adding to 28081312 its reverse (21318082), we get a palindrome (49399394).

The spelling of 28081312 in words is "twenty-eight million, eighty-one thousand, three hundred twelve".