28640115 has 32 divisors (see below), whose sum is σ = 58191360. Its totient is φ = 13092192.

The previous prime is 28640069. The next prime is 28640119. The reversal of 28640115 is 51104682.

28640115 is a `hidden beast` number, since 2 + 8 + 640 + 1 + 15 = 666.

It is not a de Polignac number, because 28640115 - 2¹⁴ = 28623731 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (28640119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14209 + ... + 16098.

It is an arithmetic number, because the mean of its divisors is an integer number (1818480).

Almost surely, 2^28640115 is an apocalyptic number.

28640115 is an abundant number, since it is smaller than the sum of its proper divisors (29551245).

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

28640115 is a wasteful number, since it uses less digits than its factorization.

28640115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30328 (or 30322 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 28640115 is about 5351.6460084725. The cubic root of 28640115 is about 305.9554914118.

Adding to 28640115 its reverse (51104682), we get a palindrome (79744797).

It can be divided in two parts, 286 and 40115, that added together give a square (40401 = 201²).

The spelling of 28640115 in words is "twenty-eight million, six hundred forty thousand, one hundred fifteen".