118091861 has 2 divisors, whose sum is σ = 118091862. Its totient is φ = 118091860.

The previous prime is 118091851. The next prime is 118091873. The reversal of 118091861 is 168190811.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 86843761 + 31248100 = 9319^2 + 5590^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-118091861 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (118091801) 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, 59045930 + 59045931.

It is an arithmetic number, because the mean of its divisors is an integer number (59045931).

Almost surely, 2^118091861 is an apocalyptic number.

It is an amenable number.

118091861 is a deficient number, since it is larger than the sum of its proper divisors (1).

118091861 is an equidigital number, since it uses as much as digits as its factorization.

118091861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 35.

The square root of 118091861 is about 10867.0079138648. The cubic root of 118091861 is about 490.6140586955.

The spelling of 118091861 in words is "one hundred eighteen million, ninety-one thousand, eight hundred sixty-one".