28478681 has 12 divisors (see below), whose sum is σ = 35775936. Its totient is φ = 22190520.

The previous prime is 28478657. The next prime is 28478683. The reversal of 28478681 is 18687482.

It is not a de Polignac number, because 28478681 - 2⁶ = 28478617 is a prime.

It is a super-2 number, since 2×28478681² = 1622070542999522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28478683) 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 11 ways as a sum of consecutive naturals, for example, 15965 + ... + 17658.

It is an arithmetic number, because the mean of its divisors is an integer number (2981328).

Almost surely, 2^28478681 is an apocalyptic number.

It is an amenable number.

28478681 is a deficient number, since it is larger than the sum of its proper divisors (7297255).

28478681 is a wasteful number, since it uses less digits than its factorization.

28478681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33652 (or 33641 counting only the distinct ones).

The product of its digits is 172032, while the sum is 44.

The square root of 28478681 is about 5336.5420451824. The cubic root of 28478681 is about 305.3795543458.

The spelling of 28478681 in words is "twenty-eight million, four hundred seventy-eight thousand, six hundred eighty-one".