721924 has 48 divisors (see below), whose sum is σ = 1612800. Its totient is φ = 275616.

The previous prime is 721921. The next prime is 721951. The reversal of 721924 is 429127.

Its product of digits (1008) is a multiple of the sum of its prime factors (112).

It is not an unprimeable number, because it can be changed into a prime (721921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12207 + ... + 12265.

It is an arithmetic number, because the mean of its divisors is an integer number (33600).

2⁷²¹⁹²⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 721924, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (806400).

721924 is an abundant number, since it is smaller than the sum of its proper divisors (890876).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

721924 is a wasteful number, since it uses less digits than its factorization.

721924 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112 (or 110 counting only the distinct ones).

The product of its digits is 1008, while the sum is 25.

The square root of 721924 is about 849.6611089134. The cubic root of 721924 is about 89.7078593196.

The spelling of 721924 in words is "seven hundred twenty-one thousand, nine hundred twenty-four".