8281181721 has 8 divisors (see below), whose sum is σ = 11044298880. Its totient is φ = 5519426192.

The previous prime is 8281181693. The next prime is 8281181731. The reversal of 8281181721 is 1271811828.

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 8281181721 - 2²⁹ = 7744310809 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 8281181721.

It is not an unprimeable number, because it can be changed into a prime (8281181731) 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, 326130 + ... + 350603.

It is an arithmetic number, because the mean of its divisors is an integer number (1380537360).

Almost surely, 2^8281181721 is an apocalyptic number.

It is an amenable number.

8281181721 is a deficient number, since it is larger than the sum of its proper divisors (2763117159).

8281181721 is a wasteful number, since it uses less digits than its factorization.

8281181721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 680815.

The product of its digits is 14336, while the sum is 39.

The square root of 8281181721 is about 91000.9984615554. The cubic root of 8281181721 is about 2023.1625232784.

The spelling of 8281181721 in words is "eight billion, two hundred eighty-one million, one hundred eighty-one thousand, seven hundred twenty-one".