28430218 has 4 divisors (see below), whose sum is σ = 42645330. Its totient is φ = 14215108.

The previous prime is 28430201. The next prime is 28430219. The reversal of 28430218 is 81203482.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81203482 = 2 ⋅40601741.

It can be written as a sum of positive squares in only one way, i.e., 14569489 + 13860729 = 3817^2 + 3723^2 .

It is not an unprimeable number, because it can be changed into a prime (28430219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7107553 + ... + 7107556.

Almost surely, 2^28430218 is an apocalyptic number.

28430218 is a deficient number, since it is larger than the sum of its proper divisors (14215112).

28430218 is a wasteful number, since it uses less digits than its factorization.

28430218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14215111.

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 28430218 is about 5331.9994373593. Note that the first 3 decimals coincide. The cubic root of 28430218 is about 305.2062315684.

The spelling of 28430218 in words is "twenty-eight million, four hundred thirty thousand, two hundred eighteen".