21742743619643 has 2 divisors, whose sum is σ = 21742743619644. Its totient is φ = 21742743619642.

The previous prime is 21742743619633. The next prime is 21742743619697. The reversal of 21742743619643 is 34691634724712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21742743619643 - 2⁶ = 21742743619579 is a prime.

It is not a weakly prime, because it can be changed into another prime (21742743619633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10871371809821 + 10871371809822.

It is an arithmetic number, because the mean of its divisors is an integer number (10871371809822).

Almost surely, 2^{21742743619643} is an apocalyptic number.

21742743619643 is a deficient number, since it is larger than the sum of its proper divisors (1).

21742743619643 is an equidigital number, since it uses as much as digits as its factorization.

21742743619643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36578304, while the sum is 59.

The spelling of 21742743619643 in words is "twenty-one trillion, seven hundred forty-two billion, seven hundred forty-three million, six hundred nineteen thousand, six hundred forty-three".