8161272720 has 160 divisors (see below), whose sum is σ = 28765123200. Its totient is φ = 2125702656.

The previous prime is 8161272709. The next prime is 8161272727. The reversal of 8161272720 is 272721618.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (8161272727) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 48946 + ... + 136814.

It is an arithmetic number, because the mean of its divisors is an integer number (179782020).

Almost surely, 2^8161272720 is an apocalyptic number.

8161272720 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8161272720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14382561600).

8161272720 is an abundant number, since it is smaller than the sum of its proper divisors (20603850480).

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

8161272720 is a wasteful number, since it uses less digits than its factorization.

8161272720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87934 (or 87922 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 8161272720 is about 90339.7626740296. The cubic root of 8161272720 is about 2013.3500827030.

The spelling of 8161272720 in words is "eight billion, one hundred sixty-one million, two hundred seventy-two thousand, seven hundred twenty".