21112103012981 has 2 divisors, whose sum is σ = 21112103012982. Its totient is φ = 21112103012980.

The previous prime is 21112103012977. The next prime is 21112103013013. The reversal of 21112103012981 is 18921030121112.

It is an a-pointer prime, because the next prime (21112103013013) can be obtained adding 21112103012981 to its sum of digits (32).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14572657282225 + 6539445730756 = 3817415^2 + 2557234^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112103012981 - 2² = 21112103012977 is a prime.

It is a super-2 number, since 2×21112103012981² (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 (21112103012951) 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, 10556051506490 + 10556051506491.

It is an arithmetic number, because the mean of its divisors is an integer number (10556051506491).

Almost surely, 2^{21112103012981} is an apocalyptic number.

It is an amenable number.

21112103012981 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112103012981 is an equidigital number, since it uses as much as digits as its factorization.

21112103012981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 32.

The spelling of 21112103012981 in words is "twenty-one trillion, one hundred twelve billion, one hundred three million, twelve thousand, nine hundred eighty-one".