2118138181 has 2 divisors, whose sum is σ = 2118138182. Its totient is φ = 2118138180.

The previous prime is 2118138167. The next prime is 2118138229. The reversal of 2118138181 is 1818318112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1733389956 + 384748225 = 41634^2 + 19615^2 .

It is a cyclic number.

It is not a de Polignac number, because 2118138181 - 2⁷ = 2118138053 is a prime.

It is a super-2 number, since 2×2118138181² = 8973018707619977522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2118138151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1059069090 + 1059069091.

It is an arithmetic number, because the mean of its divisors is an integer number (1059069091).

Almost surely, 2^2118138181 is an apocalyptic number.

It is an amenable number.

2118138181 is a deficient number, since it is larger than the sum of its proper divisors (1).

2118138181 is an equidigital number, since it uses as much as digits as its factorization.

2118138181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3072, while the sum is 34.

The square root of 2118138181 is about 46023.2352296098. The cubic root of 2118138181 is about 1284.2554859941.

The spelling of 2118138181 in words is "two billion, one hundred eighteen million, one hundred thirty-eight thousand, one hundred eighty-one".