21178817116171 has 32 divisors (see below), whose sum is σ = 25310574455040. Its totient is φ = 17466063484800.

The previous prime is 21178817116103. The next prime is 21178817116267. The reversal of 21178817116171 is 17161171887112.

It is a cyclic number.

It is not a de Polignac number, because 21178817116171 - 2²⁹ = 21178280245259 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21178817111171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28427736 + ... + 29163226.

It is an arithmetic number, because the mean of its divisors is an integer number (790955451720).

Almost surely, 2^{21178817116171} is an apocalyptic number.

21178817116171 is a deficient number, since it is larger than the sum of its proper divisors (4131757338869).

21178817116171 is a wasteful number, since it uses less digits than its factorization.

21178817116171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 738987.

The product of its digits is 263424, while the sum is 52.

The spelling of 21178817116171 in words is "twenty-one trillion, one hundred seventy-eight billion, eight hundred seventeen million, one hundred sixteen thousand, one hundred seventy-one".