120109991 has 2 divisors, whose sum is σ = 120109992. Its totient is φ = 120109990.

The previous prime is 120109931. The next prime is 120110057. The reversal of 120109991 is 199901021.

It is a weak prime.

It is an emirp because it is prime and its reverse (199901021) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 120109991 - 2¹⁴ = 120093607 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (120109931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60054995 + 60054996.

It is an arithmetic number, because the mean of its divisors is an integer number (60054996).

Almost surely, 2^120109991 is an apocalyptic number.

120109991 is a deficient number, since it is larger than the sum of its proper divisors (1).

120109991 is an equidigital number, since it uses as much as digits as its factorization.

120109991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1458, while the sum is 32.

The square root of 120109991 is about 10959.4703795393. The cubic root of 120109991 is about 493.3930694749.

The spelling of 120109991 in words is "one hundred twenty million, one hundred nine thousand, nine hundred ninety-one".