135539891 has 4 divisors (see below), whose sum is σ = 138845784. Its totient is φ = 132234000.

The previous prime is 135539867. The next prime is 135539893. The reversal of 135539891 is 198935531.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 198935531 = 11779 ⋅16889.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-135539891 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (135539893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1652885 + ... + 1652966.

It is an arithmetic number, because the mean of its divisors is an integer number (34711446).

Almost surely, 2^135539891 is an apocalyptic number.

135539891 is a deficient number, since it is larger than the sum of its proper divisors (3305893).

135539891 is an equidigital number, since it uses as much as digits as its factorization.

135539891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3305892.

The product of its digits is 145800, while the sum is 44.

The square root of 135539891 is about 11642.1600658984. The cubic root of 135539891 is about 513.6757267179.

The spelling of 135539891 in words is "one hundred thirty-five million, five hundred thirty-nine thousand, eight hundred ninety-one".