1221215020981 has 2 divisors, whose sum is σ = 1221215020982. Its totient is φ = 1221215020980.

The previous prime is 1221215020871. The next prime is 1221215021011. The reversal of 1221215020981 is 1890205121221.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1211395201956 + 9819819025 = 1100634^2 + 99095^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221215020981 - 2¹³ = 1221215012789 is a prime.

It is a super-2 number, since 2×1221215020981² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221215026981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610607510490 + 610607510491.

It is an arithmetic number, because the mean of its divisors is an integer number (610607510491).

Almost surely, 2^{1221215020981} is an apocalyptic number.

It is an amenable number.

1221215020981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221215020981 is an equidigital number, since it uses as much as digits as its factorization.

1221215020981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5760, while the sum is 34.

The spelling of 1221215020981 in words is "one trillion, two hundred twenty-one billion, two hundred fifteen million, twenty thousand, nine hundred eighty-one".