28681577 has 2 divisors, whose sum is σ = 28681578. Its totient is φ = 28681576.

The previous prime is 28681531. The next prime is 28681579. The reversal of 28681577 is 77518682.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28079401 + 602176 = 5299^2 + 776^2 .

It is a cyclic number.

It is not a de Polignac number, because 28681577 - 2¹⁶ = 28616041 is a prime.

Together with 28681579, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28681579) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14340788 + 14340789.

It is an arithmetic number, because the mean of its divisors is an integer number (14340789).

Almost surely, 2^28681577 is an apocalyptic number.

It is an amenable number.

28681577 is a deficient number, since it is larger than the sum of its proper divisors (1).

28681577 is an equidigital number, since it uses as much as digits as its factorization.

28681577 is an evil number, because the sum of its binary digits is even.

The product of its digits is 188160, while the sum is 44.

The square root of 28681577 is about 5355.5183689350. The cubic root of 28681577 is about 306.1030630951.

The spelling of 28681577 in words is "twenty-eight million, six hundred eighty-one thousand, five hundred seventy-seven".