18236413 has 4 divisors (see below), whose sum is σ = 19639228. Its totient is φ = 16833600.

The previous prime is 18236411. The next prime is 18236419. The reversal of 18236413 is 31463281.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5008644 + 13227769 = 2238^2 + 3637^2 .

It is a cyclic number.

It is not a de Polignac number, because 18236413 - 2¹ = 18236411 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18236411) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 701388 + ... + 701413.

It is an arithmetic number, because the mean of its divisors is an integer number (4909807).

Almost surely, 2^18236413 is an apocalyptic number.

18236413 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

18236413 is a deficient number, since it is larger than the sum of its proper divisors (1402815).

18236413 is a wasteful number, since it uses less digits than its factorization.

18236413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1402814.

The product of its digits is 3456, while the sum is 28.

The square root of 18236413 is about 4270.4113385012. The cubic root of 18236413 is about 263.2165180042.

Adding to 18236413 its reverse (31463281), we get a palindrome (49699694).

It can be divided in two parts, 182364 and 13, that multiplied together give a palindrome (2370732).

The spelling of 18236413 in words is "eighteen million, two hundred thirty-six thousand, four hundred thirteen".