724821 has 8 divisors (see below), whose sum is σ = 970560. Its totient is φ = 481152.

The previous prime is 724813. The next prime is 724837. The reversal of 724821 is 128427.

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

It is not a de Polignac number, because 724821 - 2³ = 724813 is a prime.

724821 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 724791 and 724800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (724021) 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 7 ways as a sum of consecutive naturals, for example, 741 + ... + 1413.

It is an arithmetic number, because the mean of its divisors is an integer number (121320).

2⁷²⁴⁸²¹ is an apocalyptic number.

It is an amenable number.

724821 is a deficient number, since it is larger than the sum of its proper divisors (245739).

724821 is a wasteful number, since it uses less digits than its factorization.

724821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1035.

The product of its digits is 896, while the sum is 24.

The square root of 724821 is about 851.3641993883. The cubic root of 724821 is about 89.8276950240.

The spelling of 724821 in words is "seven hundred twenty-four thousand, eight hundred twenty-one".