135517881 has 4 divisors (see below), whose sum is σ = 180690512. Its totient is φ = 90345252.

The previous prime is 135517859. The next prime is 135517883. The reversal of 135517881 is 188715531.

It is a happy number.

135517881 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 an emirpimes, since its reverse is a distinct semiprime: 188715531 = 3 ⋅62905177.

It is not a de Polignac number, because 135517881 - 2²³ = 127129273 is a prime.

It is a super-2 number, since 2×135517881² = 36730192141460322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (135517883) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22586311 + ... + 22586316.

It is an arithmetic number, because the mean of its divisors is an integer number (45172628).

Almost surely, 2^135517881 is an apocalyptic number.

It is an amenable number.

135517881 is a deficient number, since it is larger than the sum of its proper divisors (45172631).

135517881 is an equidigital number, since it uses as much as digits as its factorization.

135517881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45172630.

The product of its digits is 33600, while the sum is 39.

The square root of 135517881 is about 11641.2147562013. The cubic root of 135517881 is about 513.6479203536.

The spelling of 135517881 in words is "one hundred thirty-five million, five hundred seventeen thousand, eight hundred eighty-one".