1221101022091 has 2 divisors, whose sum is σ = 1221101022092. Its totient is φ = 1221101022090.

The previous prime is 1221101022047. The next prime is 1221101022109. The reversal of 1221101022091 is 1902201011221.

Together with next prime (1221101022109) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1221101022091 - 2⁹ = 1221101021579 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221101022191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610550511045 + 610550511046.

It is an arithmetic number, because the mean of its divisors is an integer number (610550511046).

Almost surely, 2^{1221101022091} is an apocalyptic number.

1221101022091 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221101022091 is an equidigital number, since it uses as much as digits as its factorization.

1221101022091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 22.

The spelling of 1221101022091 in words is "one trillion, two hundred twenty-one billion, one hundred one million, twenty-two thousand, ninety-one".