8721805971 has 8 divisors (see below), whose sum is σ = 11899518400. Its totient is φ = 5679315432.

The previous prime is 8721805951. The next prime is 8721805979. The reversal of 8721805971 is 1795081278.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 8721805971 - 2⁷ = 8721805843 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 8721805971.

It is not an unprimeable number, because it can be changed into a prime (8721805979) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33805321 + ... + 33805578.

It is an arithmetic number, because the mean of its divisors is an integer number (1487439800).

Almost surely, 2^8721805971 is an apocalyptic number.

8721805971 is a deficient number, since it is larger than the sum of its proper divisors (3177712429).

8721805971 is a wasteful number, since it uses less digits than its factorization.

8721805971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67610945.

The product of its (nonzero) digits is 282240, while the sum is 48.

The square root of 8721805971 is about 93390.6096510779. The cubic root of 8721805971 is about 2058.4270182466.

The spelling of 8721805971 in words is "eight billion, seven hundred twenty-one million, eight hundred five thousand, nine hundred seventy-one".