21617007171 has 16 divisors (see below), whose sum is σ = 30775278336. Its totient is φ = 13464180576.

The previous prime is 21617007103. The next prime is 21617007173. The reversal of 21617007171 is 17170071612.

It is not a de Polignac number, because 21617007171 - 2¹⁸ = 21616745027 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21617007173) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3639940 + ... + 3645873.

It is an arithmetic number, because the mean of its divisors is an integer number (1923454896).

Almost surely, 2^21617007171 is an apocalyptic number.

21617007171 is a deficient number, since it is larger than the sum of its proper divisors (9158271165).

21617007171 is a wasteful number, since it uses less digits than its factorization.

21617007171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7285882.

The product of its (nonzero) digits is 4116, while the sum is 33.

Adding to 21617007171 its reverse (17170071612), we get a palindrome (38787078783).

The spelling of 21617007171 in words is "twenty-one billion, six hundred seventeen million, seven thousand, one hundred seventy-one".