875721 has 32 divisors (see below), whose sum is σ = 1548288. Its totient is φ = 426240.

The previous prime is 875717. The next prime is 875731. The reversal of 875721 is 127578.

It is a happy number.

It is not a de Polignac number, because 875721 - 2² = 875717 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (875701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3816 + ... + 4038.

It is an arithmetic number, because the mean of its divisors is an integer number (48384).

2⁸⁷⁵⁷²¹ is an apocalyptic number.

It is an amenable number.

875721 is a deficient number, since it is larger than the sum of its proper divisors (672567).

875721 is a wasteful number, since it uses less digits than its factorization.

875721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261.

The product of its digits is 3920, while the sum is 30.

The square root of 875721 is about 935.7996580465. The cubic root of 875721 is about 95.6728228478.

It can be divided in two parts, 8757 and 21, that added together give a palindrome (8778).

The spelling of 875721 in words is "eight hundred seventy-five thousand, seven hundred twenty-one".