721713506 has 16 divisors (see below), whose sum is σ = 1097971200. Its totient is φ = 355737408.

The previous prime is 721713497. The next prime is 721713521. The reversal of 721713506 is 605317127.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 110426 + ... + 116778.

It is an arithmetic number, because the mean of its divisors is an integer number (68623200).

Almost surely, 2^721713506 is an apocalyptic number.

721713506 is a deficient number, since it is larger than the sum of its proper divisors (376257694).

721713506 is a wasteful number, since it uses less digits than its factorization.

721713506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7153.

The product of its (nonzero) digits is 8820, while the sum is 32.

The square root of 721713506 is about 26864.7260548102. The cubic root of 721713506 is about 896.9913965669.

The spelling of 721713506 in words is "seven hundred twenty-one million, seven hundred thirteen thousand, five hundred six".