1212101021981 has 2 divisors, whose sum is σ = 1212101021982. Its totient is φ = 1212101021980.

The previous prime is 1212101021839. The next prime is 1212101021983. The reversal of 1212101021981 is 1891201012121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 813802452100 + 398298569881 = 902110^2 + 631109^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1212101021981 is a prime.

It is a super-2 number, since 2×1212101021981² (a number of 25 digits) contains 22 as substring.

Together with 1212101021983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1212101021983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606050510990 + 606050510991.

It is an arithmetic number, because the mean of its divisors is an integer number (606050510991).

Almost surely, 2^{1212101021981} is an apocalyptic number.

It is an amenable number.

1212101021981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212101021981 is an equidigital number, since it uses as much as digits as its factorization.

1212101021981 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 29.

The spelling of 1212101021981 in words is "one trillion, two hundred twelve billion, one hundred one million, twenty-one thousand, nine hundred eighty-one".