135131534221 has 4 divisors (see below), whose sum is σ = 135409012192. Its totient is φ = 134854056252.

The previous prime is 135131534191. The next prime is 135131534227. The reversal of 135131534221 is 122435131531.

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: 122435131531 = 79133 ⋅1547207.

It is a cyclic number.

It is not a de Polignac number, because 135131534221 - 2⁵ = 135131534189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135131534227) 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, 138738255 + ... + 138739228.

It is an arithmetic number, because the mean of its divisors is an integer number (33852253048).

Almost surely, 2^135131534221 is an apocalyptic number.

It is an amenable number.

135131534221 is a deficient number, since it is larger than the sum of its proper divisors (277477971).

135131534221 is an equidigital number, since it uses as much as digits as its factorization.

135131534221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277477970.

The product of its digits is 10800, while the sum is 31.

Adding to 135131534221 its reverse (122435131531), we get a palindrome (257566665752).

The spelling of 135131534221 in words is "one hundred thirty-five billion, one hundred thirty-one million, five hundred thirty-four thousand, two hundred twenty-one".