28687489 has 2 divisors, whose sum is σ = 28687490. Its totient is φ = 28687488.

The previous prime is 28687481. The next prime is 28687499. The reversal of 28687489 is 98478682.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14938225 + 13749264 = 3865^2 + 3708^2 .

It is a cyclic number.

It is not a de Polignac number, because 28687489 - 2³ = 28687481 is a prime.

It is not a weakly prime, because it can be changed into another prime (28687481) 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, 14343744 + 14343745.

It is an arithmetic number, because the mean of its divisors is an integer number (14343745).

Almost surely, 2^28687489 is an apocalyptic number.

It is an amenable number.

28687489 is a deficient number, since it is larger than the sum of its proper divisors (1).

28687489 is an equidigital number, since it uses as much as digits as its factorization.

28687489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1548288, while the sum is 52.

The square root of 28687489 is about 5356.0702945350. The cubic root of 28687489 is about 306.1240935168.

The spelling of 28687489 in words is "twenty-eight million, six hundred eighty-seven thousand, four hundred eighty-nine".