28232857 has 4 divisors (see below), whose sum is σ = 28711440. Its totient is φ = 27754276.

The previous prime is 28232821. The next prime is 28232873. The reversal of 28232857 is 75823282.

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, and also an emirpimes, since its reverse is a distinct semiprime: 75823282 = 2 ⋅37911641.

It is a cyclic number.

It is not a de Polignac number, because 28232857 - 2²³ = 19844249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28232557) 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, 239203 + ... + 239320.

It is an arithmetic number, because the mean of its divisors is an integer number (7177860).

Almost surely, 2^28232857 is an apocalyptic number.

It is an amenable number.

28232857 is a deficient number, since it is larger than the sum of its proper divisors (478583).

28232857 is an equidigital number, since it uses as much as digits as its factorization.

28232857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478582.

The product of its digits is 53760, while the sum is 37.

The square root of 28232857 is about 5313.4599838523. The cubic root of 28232857 is about 304.4983494167.

The spelling of 28232857 in words is "twenty-eight million, two hundred thirty-two thousand, eight hundred fifty-seven".