28218685 has 8 divisors (see below), whose sum is σ = 36940896. Its totient is φ = 20522640.

The previous prime is 28218637. The next prime is 28218719. The reversal of 28218685 is 58681282.

It is a happy number.

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

It is not a de Polignac number, because 28218685 - 2¹³ = 28210493 is a prime.

It is a Duffinian number.

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, 256479 + ... + 256588.

It is an arithmetic number, because the mean of its divisors is an integer number (4617612).

Almost surely, 2^28218685 is an apocalyptic number.

It is an amenable number.

28218685 is a deficient number, since it is larger than the sum of its proper divisors (8722211).

28218685 is a wasteful number, since it uses less digits than its factorization.

28218685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 513083.

The product of its digits is 61440, while the sum is 40.

The square root of 28218685 is about 5312.1262221450. The cubic root of 28218685 is about 304.4473913803.

The spelling of 28218685 in words is "twenty-eight million, two hundred eighteen thousand, six hundred eighty-five".