8129728520 has 32 divisors (see below), whose sum is σ = 18303278400. Its totient is φ = 3249866688.

The previous prime is 8129728507. The next prime is 8129728547. The reversal of 8129728520 is 258279218.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2621 + ... + 127539.

It is an arithmetic number, because the mean of its divisors is an integer number (571977450).

Almost surely, 2^8129728520 is an apocalyptic number.

It is an amenable number.

8129728520 is an abundant number, since it is smaller than the sum of its proper divisors (10173549880).

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

8129728520 is a wasteful number, since it uses less digits than its factorization.

8129728520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126557 (or 126553 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 44.

The square root of 8129728520 is about 90165.0071812785. The cubic root of 8129728520 is about 2010.7527950933.

The spelling of 8129728520 in words is "eight billion, one hundred twenty-nine million, seven hundred twenty-eight thousand, five hundred twenty".