721626320 has 20 divisors (see below), whose sum is σ = 1677781380. Its totient is φ = 288650496.

The previous prime is 721626313. The next prime is 721626331. The reversal of 721626320 is 23626127.

It can be written as a sum of positive squares in 2 ways, for example, as 163532944 + 558093376 = 12788^2 + 23624^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

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 in 3 ways as a sum of consecutive naturals, for example, 4510085 + ... + 4510244.

It is an arithmetic number, because the mean of its divisors is an integer number (83889069).

Almost surely, 2^721626320 is an apocalyptic number.

It is an amenable number.

721626320 is an abundant number, since it is smaller than the sum of its proper divisors (956155060).

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

721626320 is a wasteful number, since it uses less digits than its factorization.

721626320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9020342 (or 9020336 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 29.

The square root of 721626320 is about 26863.1033203537. The cubic root of 721626320 is about 896.9552750123.

The spelling of 721626320 in words is "seven hundred twenty-one million, six hundred twenty-six thousand, three hundred twenty".