28357857 has 36 divisors (see below), whose sum is σ = 46794384. Its totient is φ = 17019720.

The previous prime is 28357843. The next prime is 28357859. The reversal of 28357857 is 75875382.

28357857 is a `hidden beast` number, since 28 + 3 + 578 + 57 = 666.

It is not a de Polignac number, because 28357857 - 2⁴ = 28357841 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28357859) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 275268 + ... + 275370.

It is an arithmetic number, because the mean of its divisors is an integer number (1299844).

Almost surely, 2^28357857 is an apocalyptic number.

28357857 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

28357857 is a deficient number, since it is larger than the sum of its proper divisors (18436527).

28357857 is an equidigital number, since it uses as much as digits as its factorization.

28357857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232 (or 117 counting only the distinct ones).

The product of its digits is 470400, while the sum is 45.

The square root of 28357857 is about 5325.2095733408. The cubic root of 28357857 is about 304.9470731416.

The spelling of 28357857 in words is "twenty-eight million, three hundred fifty-seven thousand, eight hundred fifty-seven".