28057231 has 2 divisors, whose sum is σ = 28057232. Its totient is φ = 28057230.

The previous prime is 28057229. The next prime is 28057241. The reversal of 28057231 is 13275082.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28057231 - 2¹ = 28057229 is a prime.

It is a super-2 number, since 2×28057231² = 1574416422774722, which contains 22 as substring.

Together with 28057229, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28057231.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28057241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14028615 + 14028616.

It is an arithmetic number, because the mean of its divisors is an integer number (14028616).

Almost surely, 2^28057231 is an apocalyptic number.

28057231 is a deficient number, since it is larger than the sum of its proper divisors (1).

28057231 is an equidigital number, since it uses as much as digits as its factorization.

28057231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 28057231 is about 5296.9076827900. The cubic root of 28057231 is about 303.8656457029.

The spelling of 28057231 in words is "twenty-eight million, fifty-seven thousand, two hundred thirty-one".