18215205 has 16 divisors (see below), whose sum is σ = 30678720. Its totient is φ = 9203328.

The previous prime is 18215189. The next prime is 18215207. The reversal of 18215205 is 50251281.

It is not a de Polignac number, because 18215205 - 2⁴ = 18215189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18215207) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31672 + ... + 32241.

It is an arithmetic number, because the mean of its divisors is an integer number (1917420).

Almost surely, 2^18215205 is an apocalyptic number.

18215205 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18215205 is a deficient number, since it is larger than the sum of its proper divisors (12463515).

18215205 is a wasteful number, since it uses less digits than its factorization.

18215205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63940.

The product of its (nonzero) digits is 800, while the sum is 24.

The square root of 18215205 is about 4267.9274829828. The cubic root of 18215205 is about 263.1144427169.

Adding to 18215205 its reverse (50251281), we get a palindrome (68466486).

The spelling of 18215205 in words is "eighteen million, two hundred fifteen thousand, two hundred five".