18404228 has 6 divisors (see below), whose sum is σ = 32207406. Its totient is φ = 9202112.

The previous prime is 18404227. The next prime is 18404231. The reversal of 18404228 is 82240481.

It can be written as a sum of positive squares in only one way, i.e., 9535744 + 8868484 = 3088^2 + 2978^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18404228.

It is not an unprimeable number, because it can be changed into a prime (18404227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2300525 + ... + 2300532.

It is an arithmetic number, because the mean of its divisors is an integer number (5367901).

Almost surely, 2^18404228 is an apocalyptic number.

It is an amenable number.

18404228 is a deficient number, since it is larger than the sum of its proper divisors (13803178).

18404228 is a wasteful number, since it uses less digits than its factorization.

18404228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4601061 (or 4601059 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 29.

The square root of 18404228 is about 4290.0149183890. The cubic root of 18404228 is about 264.0214437739.

The spelling of 18404228 in words is "eighteen million, four hundred four thousand, two hundred twenty-eight".