8707721 has 8 divisors (see below), whose sum is σ = 9522144. Its totient is φ = 7897120.

The previous prime is 8707711. The next prime is 8707747. The reversal of 8707721 is 1277078.

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

It is not a de Polignac number, because 8707721 - 2²² = 4513417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8707711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6146 + ... + 7428.

It is an arithmetic number, because the mean of its divisors is an integer number (1190268).

Almost surely, 2^8707721 is an apocalyptic number.

It is an amenable number.

8707721 is a deficient number, since it is larger than the sum of its proper divisors (814423).

8707721 is a wasteful number, since it uses less digits than its factorization.

8707721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1911.

The product of its (nonzero) digits is 5488, while the sum is 32.

The square root of 8707721 is about 2950.8847825695. The cubic root of 8707721 is about 205.7318360018.

The spelling of 8707721 in words is "eight million, seven hundred seven thousand, seven hundred twenty-one".