21110002120981 has 2 divisors, whose sum is σ = 21110002120982. Its totient is φ = 21110002120980.

The previous prime is 21110002120919. The next prime is 21110002121023. The reversal of 21110002120981 is 18902120001112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13388500540900 + 7721501580081 = 3659030^2 + 2778759^2 .

It is a cyclic number.

It is not a de Polignac number, because 21110002120981 - 2¹³ = 21110002112789 is a prime.

It is a super-2 number, since 2×21110002120981² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21110002126981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555001060490 + 10555001060491.

It is an arithmetic number, because the mean of its divisors is an integer number (10555001060491).

Almost surely, 2^{21110002120981} is an apocalyptic number.

It is an amenable number.

21110002120981 is a deficient number, since it is larger than the sum of its proper divisors (1).

21110002120981 is an equidigital number, since it uses as much as digits as its factorization.

21110002120981 is an evil number, because the sum of its binary digits is even.

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

The spelling of 21110002120981 in words is "twenty-one trillion, one hundred ten billion, two million, one hundred twenty thousand, nine hundred eighty-one".