721708816 has 10 divisors (see below), whose sum is σ = 1398310862. Its totient is φ = 360854400.

The previous prime is 721708783. The next prime is 721708849. The reversal of 721708816 is 618807127.

It is an interprime number because it is at equal distance from previous prime (721708783) and next prime (721708849).

It can be written as a sum of positive squares in only one way, i.e., 571401216 + 150307600 = 23904^2 + 12260^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 22553385 + ... + 22553416.

Almost surely, 2^721708816 is an apocalyptic number.

It is an amenable number.

721708816 is a deficient number, since it is larger than the sum of its proper divisors (676602046).

721708816 is a wasteful number, since it uses less digits than its factorization.

721708816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45106809 (or 45106803 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 40.

The square root of 721708816 is about 26864.6387654850. The cubic root of 721708816 is about 896.9894535527.

The spelling of 721708816 in words is "seven hundred twenty-one million, seven hundred eight thousand, eight hundred sixteen".