136645561 has 16 divisors (see below), whose sum is σ = 150655120. Its totient is φ = 123171840.

The previous prime is 136645559. The next prime is 136645567. The reversal of 136645561 is 165546631.

It can be written as a sum of positive squares in 8 ways, for example, as 5107600 + 131537961 = 2260^2 + 11469^2 .

It is a cyclic number.

It is not a de Polignac number, because 136645561 - 2¹ = 136645559 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 136645561.

It is not an unprimeable number, because it can be changed into a prime (136645567) 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, 102781 + ... + 104101.

It is an arithmetic number, because the mean of its divisors is an integer number (9415945).

It is a Poulet number, since it divides 2^136645560-1.

Almost surely, 2^136645561 is an apocalyptic number.

It is an amenable number.

136645561 is a deficient number, since it is larger than the sum of its proper divisors (14009559).

136645561 is a wasteful number, since it uses less digits than its factorization.

136645561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1516.

The product of its digits is 64800, while the sum is 37.

The square root of 136645561 is about 11689.5492214200. The cubic root of 136645561 is about 515.0687198964.

The spelling of 136645561 in words is "one hundred thirty-six million, six hundred forty-five thousand, five hundred sixty-one".