21611173621717 has 16 divisors (see below), whose sum is σ = 21668001016320. Its totient is φ = 21554439508800.

The previous prime is 21611173621673. The next prime is 21611173621721. The reversal of 21611173621717 is 71712637111612.

It is a cyclic number.

It is not a de Polignac number, because 21611173621717 - 2¹¹ = 21611173619669 is a prime.

It is a super-2 number, since 2×21611173621717² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21611173021717) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3265017634 + ... + 3265024252.

It is an arithmetic number, because the mean of its divisors is an integer number (1354250063520).

Almost surely, 2^{21611173621717} is an apocalyptic number.

It is an amenable number.

21611173621717 is a deficient number, since it is larger than the sum of its proper divisors (56827394603).

21611173621717 is an equidigital number, since it uses as much as digits as its factorization.

21611173621717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12444.

The product of its digits is 148176, while the sum is 46.

The spelling of 21611173621717 in words is "twenty-one trillion, six hundred eleven billion, one hundred seventy-three million, six hundred twenty-one thousand, seven hundred seventeen".