135871891 has 2 divisors, whose sum is σ = 135871892. Its totient is φ = 135871890.

The previous prime is 135871889. The next prime is 135871903. The reversal of 135871891 is 198178531.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 135871891 - 2¹ = 135871889 is a prime.

It is a super-2 number, since 2×135871891² = 36922341527831762, which contains 22 as substring.

Together with 135871889, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (135871091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67935945 + 67935946.

It is an arithmetic number, because the mean of its divisors is an integer number (67935946).

Almost surely, 2^135871891 is an apocalyptic number.

135871891 is a deficient number, since it is larger than the sum of its proper divisors (1).

135871891 is an equidigital number, since it uses as much as digits as its factorization.

135871891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60480, while the sum is 43.

The square root of 135871891 is about 11656.4098675364. The cubic root of 135871891 is about 514.0947947013.

The spelling of 135871891 in words is "one hundred thirty-five million, eight hundred seventy-one thousand, eight hundred ninety-one".