721616451 has 8 divisors (see below), whose sum is σ = 962283264. Its totient is φ = 481013640.

The previous prime is 721616449. The next prime is 721616491. The reversal of 721616451 is 154616127.

721616451 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 721616451 - 2¹ = 721616449 is a prime.

It is not an unprimeable number, because it can be changed into a prime (721616491) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26250 + ... + 46176.

It is an arithmetic number, because the mean of its divisors is an integer number (120285408).

Almost surely, 2^721616451 is an apocalyptic number.

721616451 is a deficient number, since it is larger than the sum of its proper divisors (240666813).

721616451 is a wasteful number, since it uses less digits than its factorization.

721616451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32001.

The product of its digits is 10080, while the sum is 33.

The square root of 721616451 is about 26862.9196291096. The cubic root of 721616451 is about 896.9511860577.

The spelling of 721616451 in words is "seven hundred twenty-one million, six hundred sixteen thousand, four hundred fifty-one".