21200111011993 has 2 divisors, whose sum is σ = 21200111011994. Its totient is φ = 21200111011992.

The previous prime is 21200111011957. The next prime is 21200111012023. The reversal of 21200111011993 is 39911011100212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20339134871449 + 860976140544 = 4509893^2 + 927888^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21200111011993 is a prime.

It is not a weakly prime, because it can be changed into another prime (21200111011903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600055505996 + 10600055505997.

It is an arithmetic number, because the mean of its divisors is an integer number (10600055505997).

Almost surely, 2^{21200111011993} is an apocalyptic number.

It is an amenable number.

21200111011993 is a deficient number, since it is larger than the sum of its proper divisors (1).

21200111011993 is an equidigital number, since it uses as much as digits as its factorization.

21200111011993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 972, while the sum is 31.

The spelling of 21200111011993 in words is "twenty-one trillion, two hundred billion, one hundred eleven million, eleven thousand, nine hundred ninety-three".