21617722350047 has 2 divisors, whose sum is σ = 21617722350048. Its totient is φ = 21617722350046.

The previous prime is 21617722350023. The next prime is 21617722350131. The reversal of 21617722350047 is 74005322771612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21617722350047 - 2¹⁸ = 21617722087903 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21617722349983 and 21617722350010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21617722350647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10808861175023 + 10808861175024.

It is an arithmetic number, because the mean of its divisors is an integer number (10808861175024).

Almost surely, 2^{21617722350047} is an apocalyptic number.

21617722350047 is a deficient number, since it is larger than the sum of its proper divisors (1).

21617722350047 is an equidigital number, since it uses as much as digits as its factorization.

21617722350047 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 987840, while the sum is 47.

The spelling of 21617722350047 in words is "twenty-one trillion, six hundred seventeen billion, seven hundred twenty-two million, three hundred fifty thousand, forty-seven".