721796 has 12 divisors (see below), whose sum is σ = 1297548. Its totient is φ = 351072.

The previous prime is 721793. The next prime is 721843. The reversal of 721796 is 697127.

721796 = 19² + 20² + ... + 129².

It can be written as a sum of positive squares in 2 ways, for example, as 440896 + 280900 = 664^2 + 530^2 .

It is not an unprimeable number, because it can be changed into a prime (721793) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2291 + ... + 2586.

It is an arithmetic number, because the mean of its divisors is an integer number (108129).

2⁷²¹⁷⁹⁶ is an apocalyptic number.

It is an amenable number.

721796 is a deficient number, since it is larger than the sum of its proper divisors (575752).

721796 is a wasteful number, since it uses less digits than its factorization.

721796 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4918 (or 4916 counting only the distinct ones).

The product of its digits is 5292, while the sum is 32.

The square root of 721796 is about 849.5857814253. The cubic root of 721796 is about 89.7025571526.

The spelling of 721796 in words is "seven hundred twenty-one thousand, seven hundred ninety-six".