135121345521 has 16 divisors (see below), whose sum is σ = 181145015040. Its totient is φ = 89590458240.

The previous prime is 135121345517. The next prime is 135121345559. The reversal of 135121345521 is 125543121531.

It is not a de Polignac number, because 135121345521 - 2² = 135121345517 is a prime.

It is a super-2 number, since 2×135121345521² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (135121345591) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 316551 + ... + 608643.

It is an arithmetic number, because the mean of its divisors is an integer number (11321563440).

Almost surely, 2^135121345521 is an apocalyptic number.

It is an amenable number.

135121345521 is a deficient number, since it is larger than the sum of its proper divisors (46023669519).

135121345521 is a wasteful number, since it uses less digits than its factorization.

135121345521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292936.

The product of its digits is 18000, while the sum is 33.

The spelling of 135121345521 in words is "one hundred thirty-five billion, one hundred twenty-one million, three hundred forty-five thousand, five hundred twenty-one".