721220467009 has 9 divisors (see below), whose sum is σ = 838977662691. Its totient is φ = 618183876240.

The previous prime is 721220466979. The next prime is 721220467049. The reversal of 721220467009 is 900764022127.

The square root of 721220467009 is 849247.

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., 577063564609 + 144156902400 = 759647^2 + 379680^2 .

It is not a de Polignac number, because 721220467009 - 2¹⁵ = 721220434241 is a prime.

It is not an unprimeable number, because it can be changed into a prime (721220467049) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 5884069 + ... + 6005389.

It is an arithmetic number, because the mean of its divisors is an integer number (93219740299).

Almost surely, 2^721220467009 is an apocalyptic number.

721220467009 is the 849247-th square number.

721220467009 is the 424624-th centered octagonal number.

It is an amenable number.

721220467009 is a deficient number, since it is larger than the sum of its proper divisors (117757195682).

721220467009 is an frugal number, since it uses more digits than its factorization.

721220467009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242656 (or 121328 counting only the distinct ones).

The product of its (nonzero) digits is 84672, while the sum is 40.

The spelling of 721220467009 in words is "seven hundred twenty-one billion, two hundred twenty million, four hundred sixty-seven thousand, nine".