28231513 has 2 divisors, whose sum is σ = 28231514. Its totient is φ = 28231512.

The previous prime is 28231499. The next prime is 28231523. The reversal of 28231513 is 31513282.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15784729 + 12446784 = 3973^2 + 3528^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28231513 is a prime.

It is not a weakly prime, because it can be changed into another prime (28231523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14115756 + 14115757.

It is an arithmetic number, because the mean of its divisors is an integer number (14115757).

Almost surely, 2^28231513 is an apocalyptic number.

It is an amenable number.

28231513 is a deficient number, since it is larger than the sum of its proper divisors (1).

28231513 is an equidigital number, since it uses as much as digits as its factorization.

28231513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1440, while the sum is 25.

The square root of 28231513 is about 5313.3335110832. Note that the first 3 decimals coincide. The cubic root of 28231513 is about 304.4935175492.

Adding to 28231513 its reverse (31513282), we get a palindrome (59744795).

The spelling of 28231513 in words is "twenty-eight million, two hundred thirty-one thousand, five hundred thirteen".