28997705 has 16 divisors (see below), whose sum is σ = 39960000. Its totient is φ = 19978560.

The previous prime is 28997659. The next prime is 28997707. The reversal of 28997705 is 50779982.

It is not a de Polignac number, because 28997705 - 2¹⁴ = 28981321 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 28997705.

It is not an unprimeable number, because it can be changed into a prime (28997707) 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 in 15 ways as a sum of consecutive naturals, for example, 12830 + ... + 14919.

It is an arithmetic number, because the mean of its divisors is an integer number (2497500).

Almost surely, 2^28997705 is an apocalyptic number.

It is an amenable number.

28997705 is a deficient number, since it is larger than the sum of its proper divisors (10962295).

28997705 is a wasteful number, since it uses less digits than its factorization.

28997705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27784.

The product of its (nonzero) digits is 317520, while the sum is 47.

The square root of 28997705 is about 5384.9517175180. The cubic root of 28997705 is about 307.2235777949.

The spelling of 28997705 in words is "twenty-eight million, nine hundred ninety-seven thousand, seven hundred five".