1212200101991 has 2 divisors, whose sum is σ = 1212200101992. Its totient is φ = 1212200101990.

The previous prime is 1212200101949. The next prime is 1212200102059. The reversal of 1212200101991 is 1991010022121.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1212200101991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1212200101891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606100050995 + 606100050996.

It is an arithmetic number, because the mean of its divisors is an integer number (606100050996).

Almost surely, 2^{1212200101991} is an apocalyptic number.

1212200101991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212200101991 is an equidigital number, since it uses as much as digits as its factorization.

1212200101991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 29.

The spelling of 1212200101991 in words is "one trillion, two hundred twelve billion, two hundred million, one hundred one thousand, nine hundred ninety-one".