2138536991 has 2 divisors, whose sum is σ = 2138536992. Its totient is φ = 2138536990.

The previous prime is 2138536979. The next prime is 2138536993. The reversal of 2138536991 is 1996358312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2138536991 - 2⁶ = 2138536927 is a prime.

Together with 2138536993, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2138536993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1069268495 + 1069268496.

It is an arithmetic number, because the mean of its divisors is an integer number (1069268496).

Almost surely, 2^2138536991 is an apocalyptic number.

2138536991 is a deficient number, since it is larger than the sum of its proper divisors (1).

2138536991 is an equidigital number, since it uses as much as digits as its factorization.

2138536991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 349920, while the sum is 47.

The square root of 2138536991 is about 46244.3184726513. The cubic root of 2138536991 is about 1288.3650121474.

The spelling of 2138536991 in words is "two billion, one hundred thirty-eight million, five hundred thirty-six thousand, nine hundred ninety-one".