28255681 has 8 divisors (see below), whose sum is σ = 28643264. Its totient is φ = 27870480.

The previous prime is 28255673. The next prime is 28255691. The reversal of 28255681 is 18655282.

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 28255681 - 2³ = 28255673 is a prime.

It is a super-2 number, since 2×28255681² = 1596767017547522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28255681.

It is not an unprimeable number, because it can be changed into a prime (28255691) 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 7 ways as a sum of consecutive naturals, for example, 40546 + ... + 41236.

It is an arithmetic number, because the mean of its divisors is an integer number (3580408).

Almost surely, 2^28255681 is an apocalyptic number.

It is an amenable number.

28255681 is a deficient number, since it is larger than the sum of its proper divisors (387583).

28255681 is a wasteful number, since it uses less digits than its factorization.

28255681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1191.

The product of its digits is 38400, while the sum is 37.

The square root of 28255681 is about 5315.6073030276. The cubic root of 28255681 is about 304.5803814779.

The spelling of 28255681 in words is "twenty-eight million, two hundred fifty-five thousand, six hundred eighty-one".