21222220001993 has 2 divisors, whose sum is σ = 21222220001994. Its totient is φ = 21222220001992.

The previous prime is 21222220001929. The next prime is 21222220002029. The reversal of 21222220001993 is 39910002222212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21191779523209 + 30440478784 = 4603453^2 + 174472^2 .

It is a cyclic number.

It is not a de Polignac number, because 21222220001993 - 2⁶ = 21222220001929 is a prime.

It is not a weakly prime, because it can be changed into another prime (21222220001093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611110000996 + 10611110000997.

It is an arithmetic number, because the mean of its divisors is an integer number (10611110000997).

Almost surely, 2^{21222220001993} is an apocalyptic number.

It is an amenable number.

21222220001993 is a deficient number, since it is larger than the sum of its proper divisors (1).

21222220001993 is an equidigital number, since it uses as much as digits as its factorization.

21222220001993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 35.

The spelling of 21222220001993 in words is "twenty-one trillion, two hundred twenty-two billion, two hundred twenty million, one thousand, nine hundred ninety-three".