8011721815 has 16 divisors (see below), whose sum is σ = 9718061760. Its totient is φ = 6340239360.

The previous prime is 8011721807. The next prime is 8011721833. The reversal of 8011721815 is 5181271108.

8011721815 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 8011721815 - 2³ = 8011721807 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 332247 + ... + 355543.

It is an arithmetic number, because the mean of its divisors is an integer number (607378860).

Almost surely, 2^8011721815 is an apocalyptic number.

8011721815 is a deficient number, since it is larger than the sum of its proper divisors (1706339945).

8011721815 is a wasteful number, since it uses less digits than its factorization.

8011721815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24042.

The product of its (nonzero) digits is 4480, while the sum is 34.

The square root of 8011721815 is about 89508.2220525020. Note that the first 3 decimals coincide. The cubic root of 8011721815 is about 2000.9763412180.

The spelling of 8011721815 in words is "eight billion, eleven million, seven hundred twenty-one thousand, eight hundred fifteen".