28311218 has 12 divisors (see below), whose sum is σ = 45985338. Its totient is φ = 13066560.

The previous prime is 28311211. The next prime is 28311251. The reversal of 28311218 is 81211382.

It can be written as a sum of positive squares in 3 ways, for example, as 11607649 + 16703569 = 3407^2 + 4087^2 .

It is a Harshad number since it is a multiple of its sum of digits (26).

It is not an unprimeable number, because it can be changed into a prime (28311211) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 41543 + ... + 42218.

Almost surely, 2^28311218 is an apocalyptic number.

28311218 is a deficient number, since it is larger than the sum of its proper divisors (17674120).

28311218 is a wasteful number, since it uses less digits than its factorization.

28311218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83789 (or 83776 counting only the distinct ones).

The product of its digits is 768, while the sum is 26.

The square root of 28311218 is about 5320.8286948557. The cubic root of 28311218 is about 304.7798034418.

The spelling of 28311218 in words is "twenty-eight million, three hundred eleven thousand, two hundred eighteen".