8172172806 has 64 divisors (see below), whose sum is σ = 19091444736. Its totient is φ = 2283811200.

The previous prime is 8172172763. The next prime is 8172172807. The reversal of 8172172806 is 6082712718.

It is a super-2 number, since 2×8172172806² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8172172807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 454911 + ... + 472533.

It is an arithmetic number, because the mean of its divisors is an integer number (298303824).

Almost surely, 2^8172172806 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8172172806, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9545722368).

8172172806 is an abundant number, since it is smaller than the sum of its proper divisors (10919271930).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

8172172806 is a wasteful number, since it uses less digits than its factorization.

8172172806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17877.

The product of its (nonzero) digits is 75264, while the sum is 42.

The square root of 8172172806 is about 90400.0708296183. The cubic root of 8172172806 is about 2014.2460183789.

The spelling of 8172172806 in words is "eight billion, one hundred seventy-two million, one hundred seventy-two thousand, eight hundred six".