135959881 has 4 divisors (see below), whose sum is σ = 135983232. Its totient is φ = 135936532.

The previous prime is 135959849. The next prime is 135959891. The reversal of 135959881 is 188959531.

135959881 = T₉₅₁₉ + T₉₅₂₀ + T₉₅₂₁.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 188959531 = 8539 ⋅22129.

It is a cyclic number.

It is not a de Polignac number, because 135959881 - 2⁵ = 135959849 is a prime.

It is a super-2 number, since 2×135959881² = 36970178483068322, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (135959891) 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, 4956 + ... + 17218.

It is an arithmetic number, because the mean of its divisors is an integer number (33995808).

Almost surely, 2^135959881 is an apocalyptic number.

135959881 is the 9521-st centered triangular number.

It is an amenable number.

135959881 is a deficient number, since it is larger than the sum of its proper divisors (23351).

135959881 is a wasteful number, since it uses less digits than its factorization.

135959881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23350.

The product of its digits is 388800, while the sum is 49.

The square root of 135959881 is about 11660.1835748842. The cubic root of 135959881 is about 514.2057458810.

The spelling of 135959881 in words is "one hundred thirty-five million, nine hundred fifty-nine thousand, eight hundred eighty-one".