21120001210081 has 2 divisors, whose sum is σ = 21120001210082. Its totient is φ = 21120001210080.

The previous prime is 21120001210079. The next prime is 21120001210109. The reversal of 21120001210081 is 18001210002112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20381116557025 + 738884653056 = 4514545^2 + 859584^2 .

It is a cyclic number.

It is not a de Polignac number, because 21120001210081 - 2¹ = 21120001210079 is a prime.

It is a super-2 number, since 2×21120001210081² (a number of 27 digits) contains 22 as substring.

Together with 21120001210079, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21120001210181) 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, 10560000605040 + 10560000605041.

It is an arithmetic number, because the mean of its divisors is an integer number (10560000605041).

Almost surely, 2^{21120001210081} is an apocalyptic number.

It is an amenable number.

21120001210081 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120001210081 is an equidigital number, since it uses as much as digits as its factorization.

21120001210081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21120001210081 its reverse (18001210002112), we get a palindrome (39121211212193).

The spelling of 21120001210081 in words is "twenty-one trillion, one hundred twenty billion, one million, two hundred ten thousand, eighty-one".