118517881 has 2 divisors, whose sum is σ = 118517882. Its totient is φ = 118517880.

The previous prime is 118517851. The next prime is 118517891. The reversal of 118517881 is 188715811.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62267881 + 56250000 = 7891^2 + 7500^2 .

It is an emirp because it is prime and its reverse (188715811) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 118517881 - 2⁵ = 118517849 is a prime.

It is a super-2 number, since 2×118517881² = 28092976233460322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (118517831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 59258940 + 59258941.

It is an arithmetic number, because the mean of its divisors is an integer number (59258941).

Almost surely, 2^118517881 is an apocalyptic number.

It is an amenable number.

118517881 is a deficient number, since it is larger than the sum of its proper divisors (1).

118517881 is an equidigital number, since it uses as much as digits as its factorization.

118517881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17920, while the sum is 40.

The square root of 118517881 is about 10886.5917990894. The cubic root of 118517881 is about 491.2033190778.

The spelling of 118517881 in words is "one hundred eighteen million, five hundred seventeen thousand, eight hundred eighty-one".