28581517 has 2 divisors, whose sum is σ = 28581518. Its totient is φ = 28581516.

The previous prime is 28581493. The next prime is 28581521. The reversal of 28581517 is 71518582.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22099401 + 6482116 = 4701^2 + 2546^2 .

It is a cyclic number.

It is not a de Polignac number, because 28581517 - 2⁷ = 28581389 is a prime.

It is a super-2 number, since 2×28581517² = 1633806228042578, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28581577) 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, 14290758 + 14290759.

It is an arithmetic number, because the mean of its divisors is an integer number (14290759).

Almost surely, 2^28581517 is an apocalyptic number.

It is an amenable number.

28581517 is a deficient number, since it is larger than the sum of its proper divisors (1).

28581517 is an equidigital number, since it uses as much as digits as its factorization.

28581517 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22400, while the sum is 37.

The square root of 28581517 is about 5346.1684410426. The cubic root of 28581517 is about 305.7466861396.

The spelling of 28581517 in words is "twenty-eight million, five hundred eighty-one thousand, five hundred seventeen".