1221030945091 has 2 divisors, whose sum is σ = 1221030945092. Its totient is φ = 1221030945090.

The previous prime is 1221030945089. The next prime is 1221030945109. The reversal of 1221030945091 is 1905490301221.

Together with next prime (1221030945109) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221030945091 - 2¹ = 1221030945089 is a prime.

Together with 1221030945089, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1221030945091.

It is not a weakly prime, because it can be changed into another prime (1221030942091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610515472545 + 610515472546.

It is an arithmetic number, because the mean of its divisors is an integer number (610515472546).

Almost surely, 2^{1221030945091} is an apocalyptic number.

1221030945091 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221030945091 is an equidigital number, since it uses as much as digits as its factorization.

1221030945091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19440, while the sum is 37.

The spelling of 1221030945091 in words is "one trillion, two hundred twenty-one billion, thirty million, nine hundred forty-five thousand, ninety-one".