18504216 has 24 divisors (see below), whose sum is σ = 50115780. Its totient is φ = 6168048.

The previous prime is 18504209. The next prime is 18504217. The reversal of 18504216 is 61240581.

It is a tau number, because it is divible by the number of its divisors (24).

It is a self number, because there is not a number n which added to its sum of digits gives 18504216.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18504217) 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, 128430 + ... + 128573.

Almost surely, 2^18504216 is an apocalyptic number.

It is an amenable number.

18504216 is an abundant number, since it is smaller than the sum of its proper divisors (31611564).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18504216 is a wasteful number, since it uses less digits than its factorization.

18504216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257015 (or 257008 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 18504216 is about 4301.6527056470. The cubic root of 18504216 is about 264.4987129534.

Adding to 18504216 its reverse (61240581), we get a palindrome (79744797).

The spelling of 18504216 in words is "eighteen million, five hundred four thousand, two hundred sixteen".