28787 has 4 divisors (see below), whose sum is σ = 31416. Its totient is φ = 26160.

The previous prime is 28771. The next prime is 28789. The reversal of 28787 is 78782.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28787 - 2⁴ = 28771 is a prime.

It is a plaindrome in base 12.

It is a zygodrome in base 2.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 28787.

It is not an unprimeable number, because it can be changed into a prime (28789) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1298 + ... + 1319.

It is an arithmetic number, because the mean of its divisors is an integer number (7854).

2²⁸⁷⁸⁷ is an apocalyptic number.

28787 is a deficient number, since it is larger than the sum of its proper divisors (2629).

28787 is a wasteful number, since it uses less digits than its factorization.

28787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2628.

The product of its digits is 6272, while the sum is 32.

The square root of 28787 is about 169.6673215443. The cubic root of 28787 is about 30.6477645541.

The spelling of 28787 in words is "twenty-eight thousand, seven hundred eighty-seven".