8128721276 has 12 divisors (see below), whose sum is σ = 15319513272. Its totient is φ = 3751717488.

The previous prime is 8128721269. The next prime is 8128721287. The reversal of 8128721276 is 6721278218.

It is a super-2 number, since 2×8128721276² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 78160730 + ... + 78160833.

It is an arithmetic number, because the mean of its divisors is an integer number (1276626106).

Almost surely, 2^8128721276 is an apocalyptic number.

It is an amenable number.

8128721276 is a deficient number, since it is larger than the sum of its proper divisors (7190791996).

8128721276 is a wasteful number, since it uses less digits than its factorization.

8128721276 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156321580 (or 156321578 counting only the distinct ones).

The product of its digits is 150528, while the sum is 44.

The square root of 8128721276 is about 90159.4214488980. The cubic root of 8128721276 is about 2010.6697499940.

The spelling of 8128721276 in words is "eight billion, one hundred twenty-eight million, seven hundred twenty-one thousand, two hundred seventy-six".