121021201981 has 2 divisors, whose sum is σ = 121021201982. Its totient is φ = 121021201980.

The previous prime is 121021201969. The next prime is 121021202051. The reversal of 121021201981 is 189102120121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 88292773881 + 32728428100 = 297141^2 + 180910^2 .

It is a cyclic number.

It is not a de Polignac number, because 121021201981 - 2⁷ = 121021201853 is a prime.

It is a super-2 number, since 2×121021201981² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121021241981) 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, 60510600990 + 60510600991.

It is an arithmetic number, because the mean of its divisors is an integer number (60510600991).

Almost surely, 2^121021201981 is an apocalyptic number.

It is an amenable number.

121021201981 is a deficient number, since it is larger than the sum of its proper divisors (1).

121021201981 is an equidigital number, since it uses as much as digits as its factorization.

121021201981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 28.

The spelling of 121021201981 in words is "one hundred twenty-one billion, twenty-one million, two hundred one thousand, nine hundred eighty-one".