28857533 has 4 divisors (see below), whose sum is σ = 28930620. Its totient is φ = 28784448.

The previous prime is 28857529. The next prime is 28857547. The reversal of 28857533 is 33575882.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 33575882 = 2 ⋅16787941.

It can be written as a sum of positive squares in 2 ways, for example, as 10004569 + 18852964 = 3163^2 + 4342^2 .

It is a cyclic number.

It is not a de Polignac number, because 28857533 - 2² = 28857529 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28857593) 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, 35948 + ... + 36741.

It is an arithmetic number, because the mean of its divisors is an integer number (7232655).

Almost surely, 2^28857533 is an apocalyptic number.

It is an amenable number.

28857533 is a deficient number, since it is larger than the sum of its proper divisors (73087).

28857533 is an equidigital number, since it uses as much as digits as its factorization.

28857533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73086.

The product of its digits is 201600, while the sum is 41.

The square root of 28857533 is about 5371.9207924168. The cubic root of 28857533 is about 306.7277486762.

The spelling of 28857533 in words is "twenty-eight million, eight hundred fifty-seven thousand, five hundred thirty-three".