135521439217 has 2 divisors, whose sum is σ = 135521439218. Its totient is φ = 135521439216.

The previous prime is 135521439197. The next prime is 135521439223. The reversal of 135521439217 is 712934125531.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68204023281 + 67317415936 = 261159^2 + 259456^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-135521439217 is a prime.

It is not a weakly prime, because it can be changed into another prime (135521439227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67760719608 + 67760719609.

It is an arithmetic number, because the mean of its divisors is an integer number (67760719609).

Almost surely, 2^135521439217 is an apocalyptic number.

It is an amenable number.

135521439217 is a deficient number, since it is larger than the sum of its proper divisors (1).

135521439217 is an equidigital number, since it uses as much as digits as its factorization.

135521439217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 226800, while the sum is 43.

The spelling of 135521439217 in words is "one hundred thirty-five billion, five hundred twenty-one million, four hundred thirty-nine thousand, two hundred seventeen".