21211120201993 has 2 divisors, whose sum is σ = 21211120201994. Its totient is φ = 21211120201992.

The previous prime is 21211120201991. The next prime is 21211120202117. The reversal of 21211120201993 is 39910202111212.

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., 20577945109264 + 633175092729 = 4536292^2 + 795723^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211120201993 - 2¹ = 21211120201991 is a prime.

Together with 21211120201991, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21211120201991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605560100996 + 10605560100997.

It is an arithmetic number, because the mean of its divisors is an integer number (10605560100997).

Almost surely, 2^{21211120201993} is an apocalyptic number.

It is an amenable number.

21211120201993 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211120201993 is an equidigital number, since it uses as much as digits as its factorization.

21211120201993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 34.

The spelling of 21211120201993 in words is "twenty-one trillion, two hundred eleven billion, one hundred twenty million, two hundred one thousand, nine hundred ninety-three".