17172200021 has 8 divisors (see below), whose sum is σ = 18200156184. Its totient is φ = 16146224640.

The previous prime is 17172200011. The next prime is 17172200033. The reversal of 17172200021 is 12000227171.

It can be written as a sum of positive squares in 4 ways, for example, as 4904200900 + 12267999121 = 70030^2 + 110761^2 .

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

It is not a de Polignac number, because 17172200021 - 2²² = 17168005717 is a prime.

It is a super-2 number, since 2×17172200021² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 17172200021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (17172200011) 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 7 ways as a sum of consecutive naturals, for example, 477320 + ... + 512033.

It is an arithmetic number, because the mean of its divisors is an integer number (2275019523).

Almost surely, 2^17172200021 is an apocalyptic number.

It is an amenable number.

17172200021 is a deficient number, since it is larger than the sum of its proper divisors (1027956163).

17172200021 is a wasteful number, since it uses less digits than its factorization.

17172200021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 990391.

The product of its (nonzero) digits is 392, while the sum is 23.

Adding to 17172200021 its reverse (12000227171), we get a palindrome (29172427192).

The spelling of 17172200021 in words is "seventeen billion, one hundred seventy-two million, two hundred thousand, twenty-one".