28643218 has 4 divisors (see below), whose sum is σ = 42964830. Its totient is φ = 14321608.

The previous prime is 28643207. The next prime is 28643233. The reversal of 28643218 is 81234682.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 25674489 + 2968729 = 5067^2 + 1723^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 7160803 + ... + 7160806.

Almost surely, 2^28643218 is an apocalyptic number.

28643218 is a deficient number, since it is larger than the sum of its proper divisors (14321612).

28643218 is a wasteful number, since it uses less digits than its factorization.

28643218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14321611.

The product of its digits is 18432, while the sum is 34.

The square root of 28643218 is about 5351.9359114249. The cubic root of 28643218 is about 305.9665405482.

The spelling of 28643218 in words is "twenty-eight million, six hundred forty-three thousand, two hundred eighteen".