721600 has 84 divisors (see below), whose sum is σ = 1984248. Its totient is φ = 256000.

The previous prime is 721597. The next prime is 721613. The reversal of 721600 is 6127.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17580 + ... + 17620.

It is an arithmetic number, because the mean of its divisors is an integer number (23622).

2⁷²¹⁶⁰⁰ 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 721600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (992124).

721600 is an abundant number, since it is smaller than the sum of its proper divisors (1262648).

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

721600 is a wasteful number, since it uses less digits than its factorization.

721600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74 (or 59 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 16.

The square root of 721600 is about 849.4704232638. The cubic root of 721600 is about 89.6944369945.

Adding to 721600 its reverse (6127), we get a palindrome (727727).

The spelling of 721600 in words is "seven hundred twenty-one thousand, six hundred".