135560521 has 4 divisors (see below), whose sum is σ = 135715972. Its totient is φ = 135405072.

The previous prime is 135560519. The next prime is 135560543. The reversal of 135560521 is 125065531.

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 110670400 + 24890121 = 10520^2 + 4989^2 .

It is a cyclic number.

It is not a de Polignac number, because 135560521 - 2¹ = 135560519 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 135560521.

It is not an unprimeable number, because it can be changed into a prime (135560501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 76410 + ... + 78163.

It is an arithmetic number, because the mean of its divisors is an integer number (33928993).

Almost surely, 2^135560521 is an apocalyptic number.

It is an amenable number.

135560521 is a deficient number, since it is larger than the sum of its proper divisors (155451).

135560521 is an equidigital number, since it uses as much as digits as its factorization.

135560521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155450.

The product of its (nonzero) digits is 4500, while the sum is 28.

The square root of 135560521 is about 11643.0460361539. The cubic root of 135560521 is about 513.7017869244.

The spelling of 135560521 in words is "one hundred thirty-five million, five hundred sixty thousand, five hundred twenty-one".