872721 has 8 divisors (see below), whose sum is σ = 1292960. Its totient is φ = 581796.

The previous prime is 872687. The next prime is 872731. The reversal of 872721 is 127278.

It is not a de Polignac number, because 872721 - 2⁶ = 872657 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 32323 = 872721 / (8 + 7 + 2 + 7 + 2 + 1).

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (872731) 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, 16135 + ... + 16188.

It is an arithmetic number, because the mean of its divisors is an integer number (161620).

2⁸⁷²⁷²¹ is an apocalyptic number.

It is an amenable number.

872721 is a deficient number, since it is larger than the sum of its proper divisors (420239).

872721 is a wasteful number, since it uses less digits than its factorization.

872721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32332 (or 32326 counting only the distinct ones).

The product of its digits is 1568, while the sum is 27.

The square root of 872721 is about 934.1953757111. The cubic root of 872721 is about 95.5634475084.

872721 divided by its sum of digits (27) gives a palindrome (32323).

Adding to 872721 its reverse (127278), we get a palindrome (999999).

The spelling of 872721 in words is "eight hundred seventy-two thousand, seven hundred twenty-one".