1218172718121 has 32 divisors (see below), whose sum is σ = 1742351897088. Its totient is φ = 754357094400.

The previous prime is 1218172718111. The next prime is 1218172718131.

1218172718121 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (1218172718111) and next prime (1218172718131).

It is not a de Polignac number, because 1218172718121 - 2⁵ = 1218172718089 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1218172718111) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1234480 + ... + 1990046.

It is an arithmetic number, because the mean of its divisors is an integer number (54448496784).

Almost surely, 2^{1218172718121} is an apocalyptic number.

It is an amenable number.

1218172718121 is a deficient number, since it is larger than the sum of its proper divisors (524179178967).

1218172718121 is a wasteful number, since it uses less digits than its factorization.

1218172718121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 756001.

The product of its digits is 25088, while the sum is 42.

The spelling of 1218172718121 in words is "one trillion, two hundred eighteen billion, one hundred seventy-two million, seven hundred eighteen thousand, one hundred twenty-one".