18998011 has 4 divisors (see below), whose sum is σ = 19402272. Its totient is φ = 18593752.

The previous prime is 18997997. The next prime is 18998033. The reversal of 18998011 is 11089981.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11089981 = 7 ⋅1584283.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18998011 is a prime.

It is a super-2 number, since 2×18998011² = 721848843912242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18998411) 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, 202060 + ... + 202153.

It is an arithmetic number, because the mean of its divisors is an integer number (4850568).

Almost surely, 2^18998011 is an apocalyptic number.

18998011 is a deficient number, since it is larger than the sum of its proper divisors (404261).

18998011 is an equidigital number, since it uses as much as digits as its factorization.

18998011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404260.

The product of its (nonzero) digits is 5184, while the sum is 37.

The square root of 18998011 is about 4358.6707836220. The cubic root of 18998011 is about 266.8308532299.

The spelling of 18998011 in words is "eighteen million, nine hundred ninety-eight thousand, eleven".