136561 has 8 divisors (see below), whose sum is σ = 150120. Its totient is φ = 123648.

The previous prime is 136559. The next prime is 136573. The reversal of 136561 is 165631.

It can be written as a sum of positive squares in 4 ways, for example, as 18225 + 118336 = 135^2 + 344^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 136561 - 2¹ = 136559 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (136501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 355 + ... + 631.

It is an arithmetic number, because the mean of its divisors is an integer number (18765).

2¹³⁶⁵⁶¹ is an apocalyptic number.

It is an amenable number.

136561 is a deficient number, since it is larger than the sum of its proper divisors (13559).

136561 is a wasteful number, since it uses less digits than its factorization.

136561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323.

The product of its digits is 540, while the sum is 22.

The square root of 136561 is about 369.5416079415. The cubic root of 136561 is about 51.4962450525.

The spelling of 136561 in words is "one hundred thirty-six thousand, five hundred sixty-one".