28658257 has 4 divisors (see below), whose sum is σ = 28670976. Its totient is φ = 28645540.

The previous prime is 28658249. The next prime is 28658261. The reversal of 28658257 is 75285682.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 28658257 - 2³ = 28658249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28658237) 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, 1969 + ... + 7822.

It is an arithmetic number, because the mean of its divisors is an integer number (7167744).

Almost surely, 2^28658257 is an apocalyptic number.

It is an amenable number.

28658257 is a deficient number, since it is larger than the sum of its proper divisors (12719).

28658257 is an equidigital number, since it uses as much as digits as its factorization.

28658257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12718.

The product of its digits is 268800, while the sum is 43.

The square root of 28658257 is about 5353.3407326640. The cubic root of 28658257 is about 306.0200799901.

The spelling of 28658257 in words is "twenty-eight million, six hundred fifty-eight thousand, two hundred fifty-seven".