28688705 has 16 divisors (see below), whose sum is σ = 36339840. Its totient is φ = 21698688.

The previous prime is 28688687. The next prime is 28688711. The reversal of 28688705 is 50788682.

It is a cyclic number.

It is not a de Polignac number, because 28688705 - 2¹² = 28684609 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8834 + ... + 11636.

It is an arithmetic number, because the mean of its divisors is an integer number (2271240).

Almost surely, 2^28688705 is an apocalyptic number.

It is an amenable number.

28688705 is a deficient number, since it is larger than the sum of its proper divisors (7651135).

28688705 is a wasteful number, since it uses less digits than its factorization.

28688705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2920.

The product of its (nonzero) digits is 215040, while the sum is 44.

The square root of 28688705 is about 5356.1838093927. The cubic root of 28688705 is about 306.1284187663.

The spelling of 28688705 in words is "twenty-eight million, six hundred eighty-eight thousand, seven hundred five".