21956837743 has 2 divisors, whose sum is σ = 21956837744. Its totient is φ = 21956837742.

The previous prime is 21956837729. The next prime is 21956837797. The reversal of 21956837743 is 34773865912.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21956837743 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21956832743) 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, 10978418871 + 10978418872.

It is an arithmetic number, because the mean of its divisors is an integer number (10978418872).

Almost surely, 2^21956837743 is an apocalyptic number.

21956837743 is a deficient number, since it is larger than the sum of its proper divisors (1).

21956837743 is an equidigital number, since it uses as much as digits as its factorization.

21956837743 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7620480, while the sum is 55.

The spelling of 21956837743 in words is "twenty-one billion, nine hundred fifty-six million, eight hundred thirty-seven thousand, seven hundred forty-three".