1200120191 has 4 divisors (see below), whose sum is σ = 1200229152. Its totient is φ = 1200011232.

The previous prime is 1200120179. The next prime is 1200120217. The reversal of 1200120191 is 1910210021.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1910210021 = 35759 ⋅53419.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1200120191 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1200120791) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35831 + ... + 60696.

It is an arithmetic number, because the mean of its divisors is an integer number (300057288).

Almost surely, 2^1200120191 is an apocalyptic number.

1200120191 is a deficient number, since it is larger than the sum of its proper divisors (108961).

1200120191 is an equidigital number, since it uses as much as digits as its factorization.

1200120191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108960.

The product of its (nonzero) digits is 36, while the sum is 17.

The square root of 1200120191 is about 34642.7509155956. The cubic root of 1200120191 is about 1062.6940463304.

The spelling of 1200120191 in words is "one billion, two hundred million, one hundred twenty thousand, one hundred ninety-one".