135156561 has 4 divisors (see below), whose sum is σ = 180208752. Its totient is φ = 90104372.

The previous prime is 135156547. The next prime is 135156583. The reversal of 135156561 is 165651531.

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: 165651531 = 3 ⋅55217177.

It is a cyclic number.

It is not a de Polignac number, because 135156561 - 2⁵ = 135156529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (135156521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22526091 + ... + 22526096.

It is an arithmetic number, because the mean of its divisors is an integer number (45052188).

Almost surely, 2^135156561 is an apocalyptic number.

It is an amenable number.

135156561 is a deficient number, since it is larger than the sum of its proper divisors (45052191).

135156561 is an equidigital number, since it uses as much as digits as its factorization.

135156561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45052190.

The product of its digits is 13500, while the sum is 33.

The square root of 135156561 is about 11625.6853991496. The cubic root of 135156561 is about 513.1910152029.

The spelling of 135156561 in words is "one hundred thirty-five million, one hundred fifty-six thousand, five hundred sixty-one".