8720731 has 8 divisors (see below), whose sum is σ = 8985600. Its totient is φ = 8459880.

The previous prime is 8720729. The next prime is 8720771. The reversal of 8720731 is 1370278.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 8720731 - 2¹ = 8720729 is a prime.

It is a super-2 number, since 2×8720731² = 152102298348722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 8720731.

It is not an unprimeable number, because it can be changed into a prime (8720771) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3726 + ... + 5596.

It is an arithmetic number, because the mean of its divisors is an integer number (1123200).

Almost surely, 2^8720731 is an apocalyptic number.

8720731 is a deficient number, since it is larger than the sum of its proper divisors (264869).

8720731 is a wasteful number, since it uses less digits than its factorization.

8720731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2009.

The product of its (nonzero) digits is 2352, while the sum is 28.

The square root of 8720731 is about 2953.0883833709. The cubic root of 8720731 is about 205.8342447067.

The spelling of 8720731 in words is "eight million, seven hundred twenty thousand, seven hundred thirty-one".