18540019 has 4 divisors (see below), whose sum is σ = 19179360. Its totient is φ = 17900680.

The previous prime is 18540007. The next prime is 18540031. The reversal of 18540019 is 91004581.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (18540007) and next prime (18540031).

It is a cyclic number.

It is not a de Polignac number, because 18540019 - 2¹¹ = 18537971 is a prime.

It is a super-2 number, since 2×18540019² = 687464609040722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18540719) 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, 319627 + ... + 319684.

It is an arithmetic number, because the mean of its divisors is an integer number (4794840).

Almost surely, 2^18540019 is an apocalyptic number.

18540019 is a deficient number, since it is larger than the sum of its proper divisors (639341).

18540019 is an equidigital number, since it uses as much as digits as its factorization.

18540019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 639340.

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 18540019 is about 4305.8122346428. The cubic root of 18540019 is about 264.6691920553.

It can be divided in two parts, 185 and 40019, that added together give a palindrome (40204).

The spelling of 18540019 in words is "eighteen million, five hundred forty thousand, nineteen".