2138118926681 has 2 divisors, whose sum is σ = 2138118926682. Its totient is φ = 2138118926680.

The previous prime is 2138118926663. The next prime is 2138118926689. The reversal of 2138118926681 is 1866298118312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1101469141081 + 1036649785600 = 1049509^2 + 1018160^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2138118926681 is a prime.

It is a super-2 number, since 2×2138118926681² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2138118926689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1069059463340 + 1069059463341.

It is an arithmetic number, because the mean of its divisors is an integer number (1069059463341).

Almost surely, 2^{2138118926681} is an apocalyptic number.

It is an amenable number.

2138118926681 is a deficient number, since it is larger than the sum of its proper divisors (1).

2138118926681 is an equidigital number, since it uses as much as digits as its factorization.

2138118926681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1990656, while the sum is 56.

The spelling of 2138118926681 in words is "two trillion, one hundred thirty-eight billion, one hundred eighteen million, nine hundred twenty-six thousand, six hundred eighty-one".