28120513 has 16 divisors (see below), whose sum is σ = 31132800. Its totient is φ = 25280640.

The previous prime is 28120511. The next prime is 28120577. The reversal of 28120513 is 31502182.

It is not a de Polignac number, because 28120513 - 2¹ = 28120511 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28120511) 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, 99933 + ... + 100213.

It is an arithmetic number, because the mean of its divisors is an integer number (1945800).

Almost surely, 2^28120513 is an apocalyptic number.

28120513 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

28120513 is a deficient number, since it is larger than the sum of its proper divisors (3012287).

28120513 is a wasteful number, since it uses less digits than its factorization.

28120513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 552.

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

The square root of 28120513 is about 5302.8778036082. The cubic root of 28120513 is about 304.0939265687.

Adding to 28120513 its reverse (31502182), we get a palindrome (59622695).

The spelling of 28120513 in words is "twenty-eight million, one hundred twenty thousand, five hundred thirteen".