28256215 has 16 divisors (see below), whose sum is σ = 36848448. Its totient is φ = 20676096.

The previous prime is 28256201. The next prime is 28256231. The reversal of 28256215 is 51265282.

It is a cyclic number.

It is not a de Polignac number, because 28256215 - 2¹¹ = 28254167 is a prime.

It is a super-2 number, since 2×28256215² = 1596827372252450, which contains 22 as substring.

28256215 is a modest number, since divided by 6215 gives 2825 as remainder.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5422 + ... + 9268.

It is an arithmetic number, because the mean of its divisors is an integer number (2303028).

Almost surely, 2^28256215 is an apocalyptic number.

28256215 is a deficient number, since it is larger than the sum of its proper divisors (8592233).

28256215 is a wasteful number, since it uses less digits than its factorization.

28256215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3978.

The product of its digits is 9600, while the sum is 31.

The square root of 28256215 is about 5315.6575322344. The cubic root of 28256215 is about 304.5823002059.

The spelling of 28256215 in words is "twenty-eight million, two hundred fifty-six thousand, two hundred fifteen".