28915517 has 2 divisors, whose sum is σ = 28915518. Its totient is φ = 28915516.

The previous prime is 28915507. The next prime is 28915559. The reversal of 28915517 is 71551982.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17799961 + 11115556 = 4219^2 + 3334^2 .

It is a cyclic number.

It is not a de Polignac number, because 28915517 - 2⁸ = 28915261 is a prime.

It is a super-2 number, since 2×28915517² = 1672214246754578, which contains 22 as substring.

It is a Chen prime.

It is equal to p_1794764 and since 28915517 and 1794764 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28915507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14457758 + 14457759.

It is an arithmetic number, because the mean of its divisors is an integer number (14457759).

Almost surely, 2^28915517 is an apocalyptic number.

It is an amenable number.

28915517 is a deficient number, since it is larger than the sum of its proper divisors (1).

28915517 is an equidigital number, since it uses as much as digits as its factorization.

28915517 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25200, while the sum is 38.

The square root of 28915517 is about 5377.3150363355. The cubic root of 28915517 is about 306.9330492348.

The spelling of 28915517 in words is "twenty-eight million, nine hundred fifteen thousand, five hundred seventeen".