1221012220081 has 2 divisors, whose sum is σ = 1221012220082. Its totient is φ = 1221012220080.

The previous prime is 1221012220061. The next prime is 1221012220139. The reversal of 1221012220081 is 1800222101221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 960997893025 + 260014327056 = 980305^2 + 509916^2 .

It is an emirp because it is prime and its reverse (1800222101221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221012220081 - 2²⁵ = 1220978665649 is a prime.

It is a super-2 number, since 2×1221012220081² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1221012220061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610506110040 + 610506110041.

It is an arithmetic number, because the mean of its divisors is an integer number (610506110041).

Almost surely, 2^{1221012220081} is an apocalyptic number.

It is an amenable number.

1221012220081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221012220081 is an equidigital number, since it uses as much as digits as its factorization.

1221012220081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 256, while the sum is 22.

The spelling of 1221012220081 in words is "one trillion, two hundred twenty-one billion, twelve million, two hundred twenty thousand, eighty-one".