721316 has 12 divisors (see below), whose sum is σ = 1328880. Its totient is φ = 341640.

The previous prime is 721307. The next prime is 721319. The reversal of 721316 is 613127.

It is a happy number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 721316.

It is not an unprimeable number, because it can be changed into a prime (721319) 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, 4670 + ... + 4821.

It is an arithmetic number, because the mean of its divisors is an integer number (110740).

2⁷²¹³¹⁶ is an apocalyptic number.

721316 is a gapful number since it is divisible by the number (76) formed by its first and last digit.

It is an amenable number.

721316 is a deficient number, since it is larger than the sum of its proper divisors (607564).

721316 is a wasteful number, since it uses less digits than its factorization.

721316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9514 (or 9512 counting only the distinct ones).

The product of its digits is 252, while the sum is 20.

The square root of 721316 is about 849.3032438417. The cubic root of 721316 is about 89.6826684419.

The spelling of 721316 in words is "seven hundred twenty-one thousand, three hundred sixteen".