28765291 has 4 divisors (see below), whose sum is σ = 28782000. Its totient is φ = 28748584.

The previous prime is 28765283. The next prime is 28765327. The reversal of 28765291 is 19256782.

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 28765291 - 2³ = 28765283 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28765201) 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, 5431 + ... + 9328.

It is an arithmetic number, because the mean of its divisors is an integer number (7195500).

Almost surely, 2^28765291 is an apocalyptic number.

28765291 is a deficient number, since it is larger than the sum of its proper divisors (16709).

28765291 is a wasteful number, since it uses less digits than its factorization.

28765291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16708.

The product of its digits is 60480, while the sum is 40.

The square root of 28765291 is about 5363.3283509403. The cubic root of 28765291 is about 306.4005853359.

The spelling of 28765291 in words is "twenty-eight million, seven hundred sixty-five thousand, two hundred ninety-one".