21616543353571 has 2 divisors, whose sum is σ = 21616543353572. Its totient is φ = 21616543353570.

The previous prime is 21616543353497. The next prime is 21616543353583. The reversal of 21616543353571 is 17535334561612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21616543353571 - 2⁹ = 21616543353059 is a prime.

It is not a weakly prime, because it can be changed into another prime (21616543359571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10808271676785 + 10808271676786.

It is an arithmetic number, because the mean of its divisors is an integer number (10808271676786).

Almost surely, 2^{21616543353571} is an apocalyptic number.

21616543353571 is a deficient number, since it is larger than the sum of its proper divisors (1).

21616543353571 is an equidigital number, since it uses as much as digits as its factorization.

21616543353571 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6804000, while the sum is 52.

The spelling of 21616543353571 in words is "twenty-one trillion, six hundred sixteen billion, five hundred forty-three million, three hundred fifty-three thousand, five hundred seventy-one".