8728721658 has 48 divisors (see below), whose sum is σ = 19574048520. Its totient is φ = 2807855232.

The previous prime is 8728721627. The next prime is 8728721663. The reversal of 8728721658 is 8561278278.

It can be written as a sum of positive squares in 4 ways, for example, as 7507009449 + 1221712209 = 86643^2 + 34953^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1841860 + ... + 1846592.

Almost surely, 2^8728721658 is an apocalyptic number.

8728721658 is an abundant number, since it is smaller than the sum of its proper divisors (10845326862).

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

8728721658 is a wasteful number, since it uses less digits than its factorization.

8728721658 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8303 (or 8300 counting only the distinct ones).

The product of its digits is 3010560, while the sum is 54.

The square root of 8728721658 is about 93427.6279159436. The cubic root of 8728721658 is about 2058.9709299149.

The spelling of 8728721658 in words is "eight billion, seven hundred twenty-eight million, seven hundred twenty-one thousand, six hundred fifty-eight".