18819911 has 16 divisors (see below), whose sum is σ = 21738240. Its totient is φ = 16125120.

The previous prime is 18819893. The next prime is 18819917. The reversal of 18819911 is 11991881.

It is not a de Polignac number, because 18819911 - 2⁶ = 18819847 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 (18819917) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17960 + ... + 18978.

It is an arithmetic number, because the mean of its divisors is an integer number (1358640).

Almost surely, 2^18819911 is an apocalyptic number.

18819911 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

18819911 is a deficient number, since it is larger than the sum of its proper divisors (2918329).

18819911 is a wasteful number, since it uses less digits than its factorization.

18819911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1126.

The product of its digits is 5184, while the sum is 38.

The square root of 18819911 is about 4338.1921349797. The cubic root of 18819911 is about 265.9944173174.

The spelling of 18819911 in words is "eighteen million, eight hundred nineteen thousand, nine hundred eleven".