20110212121981 has 2 divisors, whose sum is σ = 20110212121982. Its totient is φ = 20110212121980.

The previous prime is 20110212121873. The next prime is 20110212122023. The reversal of 20110212121981 is 18912121201102.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13591683156100 + 6518528965881 = 3686690^2 + 2553141^2 .

It is a cyclic number.

It is not a de Polignac number, because 20110212121981 - 2¹⁵ = 20110212089213 is a prime.

It is a super-3 number, since 3×20110212121981³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20110212121781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055106060990 + 10055106060991.

It is an arithmetic number, because the mean of its divisors is an integer number (10055106060991).

Almost surely, 2^{20110212121981} is an apocalyptic number.

It is an amenable number.

20110212121981 is a deficient number, since it is larger than the sum of its proper divisors (1).

20110212121981 is an equidigital number, since it uses as much as digits as its factorization.

20110212121981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 31.

The spelling of 20110212121981 in words is "twenty trillion, one hundred ten billion, two hundred twelve million, one hundred twenty-one thousand, nine hundred eighty-one".