18813019 has 4 divisors (see below), whose sum is σ = 19213344. Its totient is φ = 18412696.

The previous prime is 18813017. The next prime is 18813023. The reversal of 18813019 is 91031881.

18813019 = 293² + 294² + ... + 433².

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

It is a cyclic number.

It is not a de Polignac number, because 18813019 - 2¹ = 18813017 is a prime.

It is a super-2 number, since 2×18813019² = 707859367788722, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18813013) 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, 200092 + ... + 200185.

It is an arithmetic number, because the mean of its divisors is an integer number (4803336).

Almost surely, 2^18813019 is an apocalyptic number.

18813019 is a deficient number, since it is larger than the sum of its proper divisors (400325).

18813019 is an equidigital number, since it uses as much as digits as its factorization.

18813019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400324.

The product of its (nonzero) digits is 1728, while the sum is 31.

The square root of 18813019 is about 4337.3977221371. The cubic root of 18813019 is about 265.9619436011.

It can be divided in two parts, 1881 and 3019, that added together give a square (4900 = 70²).

The spelling of 18813019 in words is "eighteen million, eight hundred thirteen thousand, nineteen".