211121129981 has 2 divisors, whose sum is σ = 211121129982. Its totient is φ = 211121129980.

The previous prime is 211121129977. The next prime is 211121130013. The reversal of 211121129981 is 189921121112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 208948637881 + 2172492100 = 457109^2 + 46610^2 .

It is a cyclic number.

It is not a de Polignac number, because 211121129981 - 2² = 211121129977 is a prime.

It is a super-2 number, since 2×211121129981² (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 (211121129941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105560564990 + 105560564991.

It is an arithmetic number, because the mean of its divisors is an integer number (105560564991).

Almost surely, 2^211121129981 is an apocalyptic number.

It is an amenable number.

211121129981 is a deficient number, since it is larger than the sum of its proper divisors (1).

211121129981 is an equidigital number, since it uses as much as digits as its factorization.

211121129981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 38.

The spelling of 211121129981 in words is "two hundred eleven billion, one hundred twenty-one million, one hundred twenty-nine thousand, nine hundred eighty-one".