18121020113 has 12 divisors (see below), whose sum is σ = 21201411060. Its totient is φ = 15442513632.

The previous prime is 18121020109. The next prime is 18121020121. The reversal of 18121020113 is 31102012181.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 17644340224 + 476679889 = 132832^2 + 21833^2 .

It is not a de Polignac number, because 18121020113 - 2² = 18121020109 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18121020163) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1060358 + ... + 1077311.

It is an arithmetic number, because the mean of its divisors is an integer number (1766784255).

Almost surely, 2^18121020113 is an apocalyptic number.

It is an amenable number.

18121020113 is a deficient number, since it is larger than the sum of its proper divisors (3080390947).

18121020113 is a wasteful number, since it uses less digits than its factorization.

18121020113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2137856 (or 2137849 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 20.

Adding to 18121020113 its reverse (31102012181), we get a palindrome (49223032294).

The spelling of 18121020113 in words is "eighteen billion, one hundred twenty-one million, twenty thousand, one hundred thirteen".