21343441993 has 2 divisors, whose sum is σ = 21343441994. Its totient is φ = 21343441992.

The previous prime is 21343441991. The next prime is 21343442023. The reversal of 21343441993 is 39914434312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18341826624 + 3001615369 = 135432^2 + 54787^2 .

It is a cyclic number.

It is not a de Polignac number, because 21343441993 - 2¹ = 21343441991 is a prime.

It is a super-2 number, since 2×21343441993² (a number of 21 digits) contains 22 as substring.

Together with 21343441991, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21343441991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10671720996 + 10671720997.

It is an arithmetic number, because the mean of its divisors is an integer number (10671720997).

Almost surely, 2^21343441993 is an apocalyptic number.

It is an amenable number.

21343441993 is a deficient number, since it is larger than the sum of its proper divisors (1).

21343441993 is an equidigital number, since it uses as much as digits as its factorization.

21343441993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 279936, while the sum is 43.

The spelling of 21343441993 in words is "twenty-one billion, three hundred forty-three million, four hundred forty-one thousand, nine hundred ninety-three".