28668281 has 8 divisors (see below), whose sum is σ = 30050880. Its totient is φ = 27297072.

The previous prime is 28668257. The next prime is 28668287. The reversal of 28668281 is 18286682.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28668281 - 2⁶ = 28668217 is a prime.

It is a super-2 number, since 2×28668281² = 1643740670989922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28668287) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2546 + ... + 7988.

It is an arithmetic number, because the mean of its divisors is an integer number (3756360).

Almost surely, 2^28668281 is an apocalyptic number.

It is an amenable number.

28668281 is a deficient number, since it is larger than the sum of its proper divisors (1382599).

28668281 is a wasteful number, since it uses less digits than its factorization.

28668281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5695.

The product of its digits is 73728, while the sum is 41.

The square root of 28668281 is about 5354.2768886190. The cubic root of 28668281 is about 306.0557554291.

The spelling of 28668281 in words is "twenty-eight million, six hundred sixty-eight thousand, two hundred eighty-one".