135505510121405 has 4 divisors (see below), whose sum is σ = 162606612145692. Its totient is φ = 108404408097120.

The previous prime is 135505510121369. The next prime is 135505510121491. The reversal of 135505510121405 is 504121015505531.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 108162870419044 + 27342639702361 = 10400138^2 + 5229019^2 .

It is not a de Polignac number, because 135505510121405 - 2¹² = 135505510117309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13550551012136 + ... + 13550551012145.

It is an arithmetic number, because the mean of its divisors is an integer number (40651653036423).

Almost surely, 2^{135505510121405} is an apocalyptic number.

It is an amenable number.

135505510121405 is a deficient number, since it is larger than the sum of its proper divisors (27101102024287).

135505510121405 is an equidigital number, since it uses as much as digits as its factorization.

135505510121405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27101102024286.

The product of its (nonzero) digits is 75000, while the sum is 38.

Adding to 135505510121405 its reverse (504121015505531), we get a palindrome (639626525626936).

The spelling of 135505510121405 in words is "one hundred thirty-five trillion, five hundred five billion, five hundred ten million, one hundred twenty-one thousand, four hundred five".