21839741993 has 2 divisors, whose sum is σ = 21839741994. Its totient is φ = 21839741992.

The previous prime is 21839741927. The next prime is 21839742007. The reversal of 21839741993 is 39914793812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21805542889 + 34199104 = 147667^2 + 5848^2 .

It is a cyclic number.

It is not a de Polignac number, because 21839741993 - 2²⁰ = 21838693417 is a prime.

It is a super-2 number, since 2×21839741993² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21839741393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10919870996 + 10919870997.

It is an arithmetic number, because the mean of its divisors is an integer number (10919870997).

Almost surely, 2^21839741993 is an apocalyptic number.

It is an amenable number.

21839741993 is a deficient number, since it is larger than the sum of its proper divisors (1).

21839741993 is an equidigital number, since it uses as much as digits as its factorization.

21839741993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2939328, while the sum is 56.

The spelling of 21839741993 in words is "twenty-one billion, eight hundred thirty-nine million, seven hundred forty-one thousand, nine hundred ninety-three".