869721 has 8 divisors (see below), whose sum is σ = 1165440. Its totient is φ = 576912.

The previous prime is 869717. The next prime is 869747. The reversal of 869721 is 127968.

869721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 869721 - 2² = 869717 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (869021) 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, 111 + ... + 1323.

It is an arithmetic number, because the mean of its divisors is an integer number (145680).

2⁸⁶⁹⁷²¹ is an apocalyptic number.

It is an amenable number.

869721 is a deficient number, since it is larger than the sum of its proper divisors (295719).

869721 is a wasteful number, since it uses less digits than its factorization.

869721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1455.

The product of its digits is 6048, while the sum is 33.

The square root of 869721 is about 932.5883336178. The cubic root of 869721 is about 95.4538212272.

The spelling of 869721 in words is "eight hundred sixty-nine thousand, seven hundred twenty-one".