1221002229991 has 2 divisors, whose sum is σ = 1221002229992. Its totient is φ = 1221002229990.

The previous prime is 1221002229961. The next prime is 1221002230039. The reversal of 1221002229991 is 1999222001221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221002229991 - 2¹¹ = 1221002227943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221002229961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610501114995 + 610501114996.

It is an arithmetic number, because the mean of its divisors is an integer number (610501114996).

Almost surely, 2^{1221002229991} is an apocalyptic number.

1221002229991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221002229991 is an equidigital number, since it uses as much as digits as its factorization.

1221002229991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 40.

The spelling of 1221002229991 in words is "one trillion, two hundred twenty-one billion, two million, two hundred twenty-nine thousand, nine hundred ninety-one".