721346 has 8 divisors (see below), whose sum is σ = 1119420. Its totient is φ = 348208.

The previous prime is 721337. The next prime is 721351. The reversal of 721346 is 643127.

It can be written as a sum of positive squares in 2 ways, for example, as 664225 + 57121 = 815^2 + 239^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 721346.

It is an unprimeable number.

721346 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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, 6161 + ... + 6276.

2⁷²¹³⁴⁶ is an apocalyptic number.

721346 is a deficient number, since it is larger than the sum of its proper divisors (398074).

721346 is a wasteful number, since it uses less digits than its factorization.

721346 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12468.

The product of its digits is 1008, while the sum is 23.

The square root of 721346 is about 849.3209051943. The cubic root of 721346 is about 89.6839117448.

The spelling of 721346 in words is "seven hundred twenty-one thousand, three hundred forty-six".