8721221278 has 16 divisors (see below), whose sum is σ = 16309816704. Its totient is φ = 3397878360.

The previous prime is 8721221251. The next prime is 8721221291.

8721221278 is nontrivially palindromic in base 10.

8721221278 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 8721221278.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 28315500 + ... + 28315807.

It is an arithmetic number, because the mean of its divisors is an integer number (1019363544).

Almost surely, 2^8721221278 is an apocalyptic number.

8721221278 is a deficient number, since it is larger than the sum of its proper divisors (7588595426).

8721221278 is a wasteful number, since it uses less digits than its factorization.

8721221278 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56631327.

The product of its digits is 50176, while the sum is 40.

The square root of 8721221278 is about 93387.4792357091. The cubic root of 8721221278 is about 2058.3810195636.

The spelling of 8721221278 in words is "eight billion, seven hundred twenty-one million, two hundred twenty-one thousand, two hundred seventy-eight".