1200100999991 has 2 divisors, whose sum is σ = 1200100999992. Its totient is φ = 1200100999990.

The previous prime is 1200100999967. The next prime is 1200101000023. The reversal of 1200100999991 is 1999990010021.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1200100999991 - 2²⁶ = 1200033891127 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1200100999921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 600050499995 + 600050499996.

It is an arithmetic number, because the mean of its divisors is an integer number (600050499996).

Almost surely, 2^{1200100999991} is an apocalyptic number.

1200100999991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1200100999991 is an equidigital number, since it uses as much as digits as its factorization.

1200100999991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 118098, while the sum is 50.

The spelling of 1200100999991 in words is "one trillion, two hundred billion, one hundred million, nine hundred ninety-nine thousand, nine hundred ninety-one".