721996 has 24 divisors (see below), whose sum is σ = 1406160. Its totient is φ = 321600.

The previous prime is 721991. The next prime is 721997. The reversal of 721996 is 699127.

It is not an unprimeable number, because it can be changed into a prime (721991) 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 7 ways as a sum of consecutive naturals, for example, 2550 + ... + 2818.

It is an arithmetic number, because the mean of its divisors is an integer number (58590).

2⁷²¹⁹⁹⁶ is an apocalyptic number.

It is an amenable number.

721996 is a deficient number, since it is larger than the sum of its proper divisors (684164).

721996 is a wasteful number, since it uses less digits than its factorization.

721996 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345 (or 343 counting only the distinct ones).

The product of its digits is 6804, while the sum is 34.

The square root of 721996 is about 849.7034776909. The cubic root of 721996 is about 89.7108415130.

The spelling of 721996 in words is "seven hundred twenty-one thousand, nine hundred ninety-six".