18117121121 has 8 divisors (see below), whose sum is σ = 19773984288. Its totient is φ = 16461900000.

The previous prime is 18117121117. The next prime is 18117121147. The reversal of 18117121121 is 12112171181.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18117121121 - 2² = 18117121117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18117121111) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 387380 + ... + 431621.

It is an arithmetic number, because the mean of its divisors is an integer number (2471748036).

Almost surely, 2^18117121121 is an apocalyptic number.

18117121121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18117121121 is a deficient number, since it is larger than the sum of its proper divisors (1656863167).

18117121121 is a wasteful number, since it uses less digits than its factorization.

18117121121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 821023.

The product of its digits is 224, while the sum is 26.

The spelling of 18117121121 in words is "eighteen billion, one hundred seventeen million, one hundred twenty-one thousand, one hundred twenty-one".