121210120111981 has 2 divisors, whose sum is σ = 121210120111982. Its totient is φ = 121210120111980.

The previous prime is 121210120111979. The next prime is 121210120112009. The reversal of 121210120111981 is 189111021012121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66043106609481 + 55167013502500 = 8126691^2 + 7427450^2 .

It is a cyclic number.

It is not a de Polignac number, because 121210120111981 - 2¹ = 121210120111979 is a prime.

It is a super-2 number, since 2×121210120111981² (a number of 29 digits) contains 22 as substring.

Together with 121210120111979, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121210120111931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60605060055990 + 60605060055991.

It is an arithmetic number, because the mean of its divisors is an integer number (60605060055991).

Almost surely, 2^{121210120111981} is an apocalyptic number.

It is an amenable number.

121210120111981 is a deficient number, since it is larger than the sum of its proper divisors (1).

121210120111981 is an equidigital number, since it uses as much as digits as its factorization.

121210120111981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 31.

The spelling of 121210120111981 in words is "one hundred twenty-one trillion, two hundred ten billion, one hundred twenty million, one hundred eleven thousand, nine hundred eighty-one".