28920685 has 8 divisors (see below), whose sum is σ = 35901720. Its totient is φ = 22338624.

The previous prime is 28920677. The next prime is 28920707. The reversal of 28920685 is 58602982.

It can be written as a sum of positive squares in 4 ways, for example, as 212521 + 28708164 = 461^2 + 5358^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28920685 - 2³ = 28920677 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 99582 + ... + 99871.

It is an arithmetic number, because the mean of its divisors is an integer number (4487715).

Almost surely, 2^28920685 is an apocalyptic number.

It is an amenable number.

28920685 is a deficient number, since it is larger than the sum of its proper divisors (6981035).

28920685 is a wasteful number, since it uses less digits than its factorization.

28920685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199487.

The product of its (nonzero) digits is 69120, while the sum is 40.

The square root of 28920685 is about 5377.7955520827. The cubic root of 28920685 is about 306.9513339446.

The spelling of 28920685 in words is "twenty-eight million, nine hundred twenty thousand, six hundred eighty-five".