28915213 has 2 divisors, whose sum is σ = 28915214. Its totient is φ = 28915212.

The previous prime is 28915177. The next prime is 28915217. The reversal of 28915213 is 31251982.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15350724 + 13564489 = 3918^2 + 3683^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28915213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28915217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14457606 + 14457607.

It is an arithmetic number, because the mean of its divisors is an integer number (14457607).

Almost surely, 2^28915213 is an apocalyptic number.

It is an amenable number.

28915213 is a deficient number, since it is larger than the sum of its proper divisors (1).

28915213 is an equidigital number, since it uses as much as digits as its factorization.

28915213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4320, while the sum is 31.

The square root of 28915213 is about 5377.2867693661. The cubic root of 28915213 is about 306.9319735958.

The spelling of 28915213 in words is "twenty-eight million, nine hundred fifteen thousand, two hundred thirteen".