8756721 has 32 divisors (see below), whose sum is σ = 13824000. Its totient is φ = 5466384.

The previous prime is 8756707. The next prime is 8756771. The reversal of 8756721 is 1276578.

8756721 is nontrivially palindromic in base 14.

It is not a de Polignac number, because 8756721 - 2⁵ = 8756689 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (8756771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 36520 + ... + 36758.

It is an arithmetic number, because the mean of its divisors is an integer number (432000).

Almost surely, 2^8756721 is an apocalyptic number.

It is an amenable number.

8756721 is a deficient number, since it is larger than the sum of its proper divisors (5067279).

8756721 is a wasteful number, since it uses less digits than its factorization.

8756721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330 (or 324 counting only the distinct ones).

The product of its digits is 23520, while the sum is 36.

The square root of 8756721 is about 2959.1757298275. The cubic root of 8756721 is about 206.1170117894.

The spelling of 8756721 in words is "eight million, seven hundred fifty-six thousand, seven hundred twenty-one".