28286881 has 8 divisors (see below), whose sum is σ = 32474624. Its totient is φ = 24135840.

The previous prime is 28286873. The next prime is 28286927. The reversal of 28286881 is 18868282.

It is a happy number.

28286881 is nontrivially palindromic in base 16.

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 28286881 - 2³ = 28286873 is a prime.

It is a super-2 number, since 2×28286881² = 1600295273416322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28286821) 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, 7500 + ... + 10621.

It is an arithmetic number, because the mean of its divisors is an integer number (4059328).

Almost surely, 2^28286881 is an apocalyptic number.

It is an amenable number.

28286881 is a deficient number, since it is larger than the sum of its proper divisors (4187743).

28286881 is a wasteful number, since it uses less digits than its factorization.

28286881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18351.

The product of its digits is 98304, while the sum is 43.

The square root of 28286881 is about 5318.5412473723. The cubic root of 28286881 is about 304.6924464032.

The spelling of 28286881 in words is "twenty-eight million, two hundred eighty-six thousand, eight hundred eighty-one".