118820561 has 2 divisors, whose sum is σ = 118820562. Its totient is φ = 118820560.

The previous prime is 118820549. The next prime is 118820591. The reversal of 118820561 is 165028811.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 114490000 + 4330561 = 10700^2 + 2081^2 .

It is an emirp because it is prime and its reverse (165028811) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 118820561 - 2¹⁰ = 118819537 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (118820521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 59410280 + 59410281.

It is an arithmetic number, because the mean of its divisors is an integer number (59410281).

Almost surely, 2^118820561 is an apocalyptic number.

It is an amenable number.

118820561 is a deficient number, since it is larger than the sum of its proper divisors (1).

118820561 is an equidigital number, since it uses as much as digits as its factorization.

118820561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3840, while the sum is 32.

The square root of 118820561 is about 10900.4844387761. The cubic root of 118820561 is about 491.6211211026.

The spelling of 118820561 in words is "one hundred eighteen million, eight hundred twenty thousand, five hundred sixty-one".