2121021200981 has 2 divisors, whose sum is σ = 2121021200982. Its totient is φ = 2121021200980.

The previous prime is 2121021200959. The next prime is 2121021201043. The reversal of 2121021200981 is 1890021201212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1391064560356 + 729956640625 = 1179434^2 + 854375^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121021200981 - 2¹⁸ = 2121020938837 is a prime.

It is a super-2 number, since 2×2121021200981² (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 (2121021200281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060510600490 + 1060510600491.

It is an arithmetic number, because the mean of its divisors is an integer number (1060510600491).

Almost surely, 2^{2121021200981} is an apocalyptic number.

It is an amenable number.

2121021200981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121021200981 is an equidigital number, since it uses as much as digits as its factorization.

2121021200981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 29.

The spelling of 2121021200981 in words is "two trillion, one hundred twenty-one billion, twenty-one million, two hundred thousand, nine hundred eighty-one".