28280218 has 4 divisors (see below), whose sum is σ = 42420330. Its totient is φ = 14140108.

The previous prime is 28280209. The next prime is 28280237. The reversal of 28280218 is 81208282.

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., 26759929 + 1520289 = 5173^2 + 1233^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 28280218.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7070053 + ... + 7070056.

Almost surely, 2^28280218 is an apocalyptic number.

28280218 is a deficient number, since it is larger than the sum of its proper divisors (14140112).

28280218 is a wasteful number, since it uses less digits than its factorization.

28280218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14140111.

The product of its (nonzero) digits is 4096, while the sum is 31.

The square root of 28280218 is about 5317.9148169184. The cubic root of 28280218 is about 304.6685209988.

The spelling of 28280218 in words is "twenty-eight million, two hundred eighty thousand, two hundred eighteen".