8721352861 has 4 divisors (see below), whose sum is σ = 9392226172. Its totient is φ = 8050479552.

The previous prime is 8721352859. The next prime is 8721352873. The reversal of 8721352861 is 1682531278.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1682531278 = 2 ⋅841265639.

It can be written as a sum of positive squares in 2 ways, for example, as 2481932761 + 6239420100 = 49819^2 + 78990^2 .

It is a cyclic number.

It is not a de Polignac number, because 8721352861 - 2¹ = 8721352859 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8721352841) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 335436636 + ... + 335436661.

It is an arithmetic number, because the mean of its divisors is an integer number (2348056543).

Almost surely, 2^8721352861 is an apocalyptic number.

It is an amenable number.

8721352861 is a deficient number, since it is larger than the sum of its proper divisors (670873311).

8721352861 is a wasteful number, since it uses less digits than its factorization.

8721352861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 670873310.

The product of its digits is 161280, while the sum is 43.

The square root of 8721352861 is about 93388.1837332754. The cubic root of 8721352861 is about 2058.3913715766.

The spelling of 8721352861 in words is "eight billion, seven hundred twenty-one million, three hundred fifty-two thousand, eight hundred sixty-one".