724728621 has 4 divisors (see below), whose sum is σ = 966304832. Its totient is φ = 483152412.

The previous prime is 724728619. The next prime is 724728629. The reversal of 724728621 is 126827427.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 724728621 - 2¹ = 724728619 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 724728621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (724728629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120788101 + ... + 120788106.

It is an arithmetic number, because the mean of its divisors is an integer number (241576208).

Almost surely, 2^724728621 is an apocalyptic number.

It is an amenable number.

724728621 is a deficient number, since it is larger than the sum of its proper divisors (241576211).

724728621 is a wasteful number, since it uses less digits than its factorization.

724728621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241576210.

The product of its digits is 75264, while the sum is 39.

The square root of 724728621 is about 26920.7841824862. The cubic root of 724728621 is about 898.2387865872.

The spelling of 724728621 in words is "seven hundred twenty-four million, seven hundred twenty-eight thousand, six hundred twenty-one".