1200200001991 has 2 divisors, whose sum is σ = 1200200001992. Its totient is φ = 1200200001990.

The previous prime is 1200200001937. The next prime is 1200200002003. The reversal of 1200200001991 is 1991000020021.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1200200001991 - 2⁷ = 1200200001863 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1200200001901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 600100000995 + 600100000996.

It is an arithmetic number, because the mean of its divisors is an integer number (600100000996).

Almost surely, 2^{1200200001991} is an apocalyptic number.

1200200001991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1200200001991 is an equidigital number, since it uses as much as digits as its factorization.

1200200001991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 25.

The spelling of 1200200001991 in words is "one trillion, two hundred billion, two hundred million, one thousand, nine hundred ninety-one".