1221121199939 has 2 divisors, whose sum is σ = 1221121199940. Its totient is φ = 1221121199938.

The previous prime is 1221121199929. The next prime is 1221121200029. The reversal of 1221121199939 is 9399911211221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221121199939 - 2⁴⁰ = 121609572163 is a prime.

It is a super-2 number, since 2×1221121199939² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1221121199929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610560599969 + 610560599970.

It is an arithmetic number, because the mean of its divisors is an integer number (610560599970).

Almost surely, 2^{1221121199939} is an apocalyptic number.

1221121199939 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221121199939 is an equidigital number, since it uses as much as digits as its factorization.

1221121199939 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 157464, while the sum is 50.

The spelling of 1221121199939 in words is "one trillion, two hundred twenty-one billion, one hundred twenty-one million, one hundred ninety-nine thousand, nine hundred thirty-nine".