135507561 has 16 divisors (see below), whose sum is σ = 218634624. Its totient is φ = 72877824.

The previous prime is 135507553. The next prime is 135507571. The reversal of 135507561 is 165705531.

It is not a de Polignac number, because 135507561 - 2³ = 135507553 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (135507571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 189430 + ... + 190143.

It is an arithmetic number, because the mean of its divisors is an integer number (13664664).

Almost surely, 2^135507561 is an apocalyptic number.

It is an amenable number.

135507561 is a deficient number, since it is larger than the sum of its proper divisors (83127063).

135507561 is a wasteful number, since it uses less digits than its factorization.

135507561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 379600.

The product of its (nonzero) digits is 15750, while the sum is 33.

The square root of 135507561 is about 11640.7714950513. The cubic root of 135507561 is about 513.6348815303.

The spelling of 135507561 in words is "one hundred thirty-five million, five hundred seven thousand, five hundred sixty-one".