724885721 has 4 divisors (see below), whose sum is σ = 828440832. Its totient is φ = 621330612.

The previous prime is 724885703. The next prime is 724885727. The reversal of 724885721 is 127588427.

724885721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 724885721 - 2⁶ = 724885657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (724885727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51777545 + ... + 51777558.

It is an arithmetic number, because the mean of its divisors is an integer number (207110208).

Almost surely, 2^724885721 is an apocalyptic number.

It is an amenable number.

724885721 is a deficient number, since it is larger than the sum of its proper divisors (103555111).

724885721 is a wasteful number, since it uses less digits than its factorization.

724885721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103555110.

The product of its digits is 250880, while the sum is 44.

The square root of 724885721 is about 26923.7018442858. The cubic root of 724885721 is about 898.3036858769.

The spelling of 724885721 in words is "seven hundred twenty-four million, eight hundred eighty-five thousand, seven hundred twenty-one".