102020211211981 has 2 divisors, whose sum is σ = 102020211211982. Its totient is φ = 102020211211980.

The previous prime is 102020211211979. The next prime is 102020211212113. The reversal of 102020211211981 is 189112112020201.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 53990238318025 + 48029972893956 = 7347805^2 + 6930366^2 .

It is a cyclic number.

It is not a de Polignac number, because 102020211211981 - 2¹ = 102020211211979 is a prime.

It is a super-2 number, since 2×102020211211981² (a number of 29 digits) contains 22 as substring.

Together with 102020211211979, 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 (102020211211931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51010105605990 + 51010105605991.

It is an arithmetic number, because the mean of its divisors is an integer number (51010105605991).

Almost surely, 2^{102020211211981} is an apocalyptic number.

It is an amenable number.

102020211211981 is a deficient number, since it is larger than the sum of its proper divisors (1).

102020211211981 is an equidigital number, since it uses as much as digits as its factorization.

102020211211981 is an odious number, because the sum of its binary digits is odd.

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

The spelling of 102020211211981 in words is "one hundred two trillion, twenty billion, two hundred eleven million, two hundred eleven thousand, nine hundred eighty-one".