8752721 has 4 divisors (see below), whose sum is σ = 8966244. Its totient is φ = 8539200.

The previous prime is 8752717. The next prime is 8752741. The reversal of 8752721 is 1272578.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2676496 + 6076225 = 1636^2 + 2465^2 .

It is a cyclic number.

It is not a de Polignac number, because 8752721 - 2² = 8752717 is a prime.

It is a super-2 number, since 2×8752721² = 153220249807682, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (8752741) 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, 106700 + ... + 106781.

It is an arithmetic number, because the mean of its divisors is an integer number (2241561).

Almost surely, 2^8752721 is an apocalyptic number.

It is an amenable number.

8752721 is a deficient number, since it is larger than the sum of its proper divisors (213523).

8752721 is a wasteful number, since it uses less digits than its factorization.

8752721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213522.

The product of its digits is 7840, while the sum is 32.

The square root of 8752721 is about 2958.4997887443. The cubic root of 8752721 is about 206.0856228096.

The spelling of 8752721 in words is "eight million, seven hundred fifty-two thousand, seven hundred twenty-one".