28218775 has 18 divisors (see below), whose sum is σ = 37895640. Its totient is φ = 20835360.

The previous prime is 28218767. The next prime is 28218787. The reversal of 28218775 is 57781282.

It is not a de Polignac number, because 28218775 - 2³ = 28218767 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 886 + ... + 7564.

Almost surely, 2^28218775 is an apocalyptic number.

28218775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

28218775 is a deficient number, since it is larger than the sum of its proper divisors (9676865).

28218775 is a wasteful number, since it uses less digits than its factorization.

28218775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6715 (or 6697 counting only the distinct ones).

The product of its digits is 62720, while the sum is 40.

The square root of 28218775 is about 5312.1346933225. The cubic root of 28218775 is about 304.4477150457.

The spelling of 28218775 in words is "twenty-eight million, two hundred eighteen thousand, seven hundred seventy-five".