28088681 has 4 divisors (see below), whose sum is σ = 29309952. Its totient is φ = 26867412.

The previous prime is 28088659. The next prime is 28088729. The reversal of 28088681 is 18688082.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28088681 is a prime.

It is a super-2 number, since 2×28088681² = 1577948000639522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28081681) 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 3 ways as a sum of consecutive naturals, for example, 610601 + ... + 610646.

It is an arithmetic number, because the mean of its divisors is an integer number (7327488).

Almost surely, 2^28088681 is an apocalyptic number.

It is an amenable number.

28088681 is a deficient number, since it is larger than the sum of its proper divisors (1221271).

28088681 is a wasteful number, since it uses less digits than its factorization.

28088681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1221270.

The product of its (nonzero) digits is 49152, while the sum is 41.

The square root of 28088681 is about 5299.8755645770. The cubic root of 28088681 is about 303.9791399872.

The spelling of 28088681 in words is "twenty-eight million, eighty-eight thousand, six hundred eighty-one".