28531033 has 4 divisors (see below), whose sum is σ = 29302180. Its totient is φ = 27759888.

The previous prime is 28530979. The next prime is 28531051. The reversal of 28531033 is 33013582.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 27594009 + 937024 = 5253^2 + 968^2 .

It is a cyclic number.

It is not a de Polignac number, because 28531033 - 2⁹ = 28530521 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28530989 and 28531007.

It is not an unprimeable number, because it can be changed into a prime (28531073) 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, 385518 + ... + 385591.

It is an arithmetic number, because the mean of its divisors is an integer number (7325545).

Almost surely, 2^28531033 is an apocalyptic number.

It is an amenable number.

28531033 is a deficient number, since it is larger than the sum of its proper divisors (771147).

28531033 is an equidigital number, since it uses as much as digits as its factorization.

28531033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 771146.

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 28531033 is about 5341.4448419880. Note that the first 3 decimals coincide. The cubic root of 28531033 is about 305.5665649269.

The spelling of 28531033 in words is "twenty-eight million, five hundred thirty-one thousand, thirty-three".