804721 has 4 divisors (see below), whose sum is σ = 832500. Its totient is φ = 776944.

The previous prime is 804709. The next prime is 804743. The reversal of 804721 is 127408.

804721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 314721 + 490000 = 561^2 + 700^2 .

It is a cyclic number.

It is not a de Polignac number, because 804721 - 2⁵ = 804689 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is a junction number, because it is equal to n+sod(n) for n = 804692 and 804701.

It is not an unprimeable number, because it can be changed into a prime (804751) 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, 13846 + ... + 13903.

It is an arithmetic number, because the mean of its divisors is an integer number (208125).

2⁸⁰⁴⁷²¹ is an apocalyptic number.

804721 is the 480-th centered heptagonal number.

It is an amenable number.

804721 is a deficient number, since it is larger than the sum of its proper divisors (27779).

804721 is a wasteful number, since it uses less digits than its factorization.

804721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27778.

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 804721 is about 897.0624281509. The cubic root of 804721 is about 93.0140264811.

The spelling of 804721 in words is "eight hundred four thousand, seven hundred twenty-one".