1021201219981 has 2 divisors, whose sum is σ = 1021201219982. Its totient is φ = 1021201219980.

The previous prime is 1021201219967. The next prime is 1021201220021. The reversal of 1021201219981 is 1899121021201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1015670918025 + 5530301956 = 1007805^2 + 74366^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021201219981 - 2¹⁹ = 1021200695693 is a prime.

It is a super-2 number, since 2×1021201219981² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1021201219981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1021201219921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510600609990 + 510600609991.

It is an arithmetic number, because the mean of its divisors is an integer number (510600609991).

Almost surely, 2^{1021201219981} is an apocalyptic number.

It is an amenable number.

1021201219981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021201219981 is an equidigital number, since it uses as much as digits as its factorization.

1021201219981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 37.

The spelling of 1021201219981 in words is "one trillion, twenty-one billion, two hundred one million, two hundred nineteen thousand, nine hundred eighty-one".