18840413 has 4 divisors (see below), whose sum is σ = 18913980. Its totient is φ = 18766848.

The previous prime is 18840397. The next prime is 18840433. The reversal of 18840413 is 31404881.

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 11539609 + 7300804 = 3397^2 + 2702^2 .

It is a cyclic number.

It is not a de Polignac number, because 18840413 - 2⁴ = 18840397 is a prime.

It is a super-2 number, since 2×18840413² = 709922324021138, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18840433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36398 + ... + 36911.

It is an arithmetic number, because the mean of its divisors is an integer number (4728495).

Almost surely, 2^18840413 is an apocalyptic number.

It is an amenable number.

18840413 is a deficient number, since it is larger than the sum of its proper divisors (73567).

18840413 is an equidigital number, since it uses as much as digits as its factorization.

18840413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73566.

The product of its (nonzero) digits is 3072, while the sum is 29.

The square root of 18840413 is about 4340.5544576701. The cubic root of 18840413 is about 266.0909717673.

The spelling of 18840413 in words is "eighteen million, eight hundred forty thousand, four hundred thirteen".