118861991 has 2 divisors, whose sum is σ = 118861992. Its totient is φ = 118861990.

The previous prime is 118861979. The next prime is 118862021. The reversal of 118861991 is 199168811.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 118861991 - 2⁶ = 118861927 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (118861291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 59430995 + 59430996.

It is an arithmetic number, because the mean of its divisors is an integer number (59430996).

Almost surely, 2^118861991 is an apocalyptic number.

118861991 is a deficient number, since it is larger than the sum of its proper divisors (1).

118861991 is an equidigital number, since it uses as much as digits as its factorization.

118861991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 44.

The square root of 118861991 is about 10902.3846474063. The cubic root of 118861991 is about 491.6782534599.

The spelling of 118861991 in words is "one hundred eighteen million, eight hundred sixty-one thousand, nine hundred ninety-one".