1221212010191 has 2 divisors, whose sum is σ = 1221212010192. Its totient is φ = 1221212010190.

The previous prime is 1221212010167. The next prime is 1221212010241. The reversal of 1221212010191 is 1910102121221.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221212010191 - 2¹⁸ = 1221211748047 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221212010691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610606005095 + 610606005096.

It is an arithmetic number, because the mean of its divisors is an integer number (610606005096).

Almost surely, 2^{1221212010191} is an apocalyptic number.

1221212010191 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221212010191 is an equidigital number, since it uses as much as digits as its factorization.

1221212010191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 23.

It can be divided in two parts, 122121 and 2010191, that added together give a palindrome (2132312).

The spelling of 1221212010191 in words is "one trillion, two hundred twenty-one billion, two hundred twelve million, ten thousand, one hundred ninety-one".