721029904 has 75 divisors (see below), whose sum is σ = 1641713717. Its totient is φ = 306757248.

The previous prime is 721029893. The next prime is 721029913. The reversal of 721029904 is 409920127.

It is a happy number.

The square root of 721029904 is 26852.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 423536400 + 297493504 = 20580^2 + 17248^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 721029904.

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 14 ways as a sum of consecutive naturals, for example, 5262924 + ... + 5263060.

Almost surely, 2^721029904 is an apocalyptic number.

721029904 is the 26852-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 721029904

721029904 is an abundant number, since it is smaller than the sum of its proper divisors (920683813).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

721029904 is an frugal number, since it uses more digits than its factorization.

721029904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310 (or 146 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 34.

The cubic root of 721029904 is about 896.7080991037.

The spelling of 721029904 in words is "seven hundred twenty-one million, twenty-nine thousand, nine hundred four".