8732721 has 4 divisors (see below), whose sum is σ = 11643632. Its totient is φ = 5821812.

The previous prime is 8732719. The next prime is 8732743. The reversal of 8732721 is 1272378.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 8732721 - 2¹ = 8732719 is a prime.

It is a Duffinian number.

It is a plaindrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (8732921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1455451 + ... + 1455456.

It is an arithmetic number, because the mean of its divisors is an integer number (2910908).

Almost surely, 2^8732721 is an apocalyptic number.

It is an amenable number.

8732721 is a deficient number, since it is larger than the sum of its proper divisors (2910911).

8732721 is a wasteful number, since it uses less digits than its factorization.

8732721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2910910.

The product of its digits is 4704, while the sum is 30.

The square root of 8732721 is about 2955.1177641509. The cubic root of 8732721 is about 205.9285342950.

It can be divided in two parts, 8732 and 721, that added together give a triangular number (9453 = T₁₃₇).

The spelling of 8732721 in words is "eight million, seven hundred thirty-two thousand, seven hundred twenty-one".