1221210101191 has 2 divisors, whose sum is σ = 1221210101192. Its totient is φ = 1221210101190.

The previous prime is 1221210101149. The next prime is 1221210101201. The reversal of 1221210101191 is 1911010121221.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1221210101191 - 2¹⁵ = 1221210068423 is a prime.

It is a super-2 number, since 2×1221210101191² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221210101101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610605050595 + 610605050596.

It is an arithmetic number, because the mean of its divisors is an integer number (610605050596).

Almost surely, 2^{1221210101191} is an apocalyptic number.

1221210101191 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221210101191 is an equidigital number, since it uses as much as digits as its factorization.

1221210101191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 22.

The spelling of 1221210101191 in words is "one trillion, two hundred twenty-one billion, two hundred ten million, one hundred one thousand, one hundred ninety-one".