28218019 has 8 divisors (see below), whose sum is σ = 28951472. Its totient is φ = 27488160.

The previous prime is 28218017. The next prime is 28218053. The reversal of 28218019 is 91081282.

It is a happy number.

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 28218019 - 2¹ = 28218017 is a prime.

It is a super-2 number, since 2×28218019² = 1592513192568722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28218017) 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 7 ways as a sum of consecutive naturals, for example, 22657 + ... + 23869.

It is an arithmetic number, because the mean of its divisors is an integer number (3618934).

Almost surely, 2^28218019 is an apocalyptic number.

28218019 is a deficient number, since it is larger than the sum of its proper divisors (733453).

28218019 is a wasteful number, since it uses less digits than its factorization.

28218019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1797.

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 28218019 is about 5312.0635350116. The cubic root of 28218019 is about 304.4449962349. Note that the first 3 decimals are identical.

The spelling of 28218019 in words is "twenty-eight million, two hundred eighteen thousand, nineteen".