118688561 has 4 divisors (see below), whose sum is σ = 122781300. Its totient is φ = 114595824.

The previous prime is 118688551. The next prime is 118688593. The reversal of 118688561 is 165886811.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 165886811 = 1187 ⋅139753.

It can be written as a sum of positive squares in 2 ways, for example, as 99600400 + 19088161 = 9980^2 + 4369^2 .

It is a cyclic number.

It is not a de Polignac number, because 118688561 - 2¹⁰ = 118687537 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (118688551) 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, 2046326 + ... + 2046383.

It is an arithmetic number, because the mean of its divisors is an integer number (30695325).

Almost surely, 2^118688561 is an apocalyptic number.

It is an amenable number.

118688561 is a deficient number, since it is larger than the sum of its proper divisors (4092739).

118688561 is an equidigital number, since it uses as much as digits as its factorization.

118688561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4092738.

The product of its digits is 92160, while the sum is 44.

The square root of 118688561 is about 10894.4279794765. The cubic root of 118688561 is about 491.4390032578.

The spelling of 118688561 in words is "one hundred eighteen million, six hundred eighty-eight thousand, five hundred sixty-one".