21200021171 has 8 divisors (see below), whose sum is σ = 24232158720. Its totient is φ = 18168774408.

The previous prime is 21200021149. The next prime is 21200021189. The reversal of 21200021171 is 17112000212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21200021171 - 2⁶ = 21200021107 is a prime.

It is a super-2 number, since 2×21200021171² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21200021111) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 170891 + ... + 267588.

It is an arithmetic number, because the mean of its divisors is an integer number (3029019840).

Almost surely, 2^21200021171 is an apocalyptic number.

21200021171 is a deficient number, since it is larger than the sum of its proper divisors (3032137549).

21200021171 is an equidigital number, since it uses as much as digits as its factorization.

21200021171 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 445393.

The product of its (nonzero) digits is 56, while the sum is 17.

Adding to 21200021171 its reverse (17112000212), we get a palindrome (38312021383).

The spelling of 21200021171 in words is "twenty-one billion, two hundred million, twenty-one thousand, one hundred seventy-one".