8721065 has 4 divisors (see below), whose sum is σ = 10465284. Its totient is φ = 6976848.

The previous prime is 8721061. The next prime is 8721077. The reversal of 8721065 is 5601278.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5601278 = 2 ⋅2800639.

It can be written as a sum of positive squares in 2 ways, for example, as 1175056 + 7546009 = 1084^2 + 2747^2 .

It is a cyclic number.

It is not a de Polignac number, because 8721065 - 2² = 8721061 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8721061) 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, 872102 + ... + 872111.

It is an arithmetic number, because the mean of its divisors is an integer number (2616321).

Almost surely, 2^8721065 is an apocalyptic number.

It is an amenable number.

8721065 is a deficient number, since it is larger than the sum of its proper divisors (1744219).

8721065 is a wasteful number, since it uses less digits than its factorization.

8721065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1744218.

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 8721065 is about 2953.1449337952. The cubic root of 8721065 is about 205.8368724589.

It can be divided in two parts, 87 and 21065, that multiplied together give a triangular number (1832655 = T₁₉₁₄).

The spelling of 8721065 in words is "eight million, seven hundred twenty-one thousand, sixty-five".