721860 has 48 divisors (see below), whose sum is σ = 2068416. Its totient is φ = 188032.

The previous prime is 721859. The next prime is 721883. The reversal of 721860 is 68127.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 721860.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3067 + ... + 3293.

It is an arithmetic number, because the mean of its divisors is an integer number (43092).

2⁷²¹⁸⁶⁰ 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 721860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1034208).

721860 is an abundant number, since it is smaller than the sum of its proper divisors (1346556).

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

721860 is a wasteful number, since it uses less digits than its factorization.

721860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292 (or 290 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 721860 is about 849.6234460042. The cubic root of 721860 is about 89.7052083144.

Adding to 721860 its reverse (68127), we get a palindrome (789987).

The spelling of 721860 in words is "seven hundred twenty-one thousand, eight hundred sixty".