28020287 has 4 divisors (see below), whose sum is σ = 28031136. Its totient is φ = 28009440.

The previous prime is 28020277. The next prime is 28020299. The reversal of 28020287 is 78202082.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28020287 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28020217) 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, 938 + ... + 7544.

It is an arithmetic number, because the mean of its divisors is an integer number (7007784).

Almost surely, 2^28020287 is an apocalyptic number.

28020287 is a deficient number, since it is larger than the sum of its proper divisors (10849).

28020287 is an equidigital number, since it uses as much as digits as its factorization.

28020287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10848.

The product of its (nonzero) digits is 3584, while the sum is 29.

The square root of 28020287 is about 5293.4192163478. The cubic root of 28020287 is about 303.7322167215.

The spelling of 28020287 in words is "twenty-eight million, twenty thousand, two hundred eighty-seven".