724840639 has 4 divisors (see below), whose sum is σ = 735659224. Its totient is φ = 714022056.

The previous prime is 724840603. The next prime is 724840651. The reversal of 724840639 is 936048427.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-724840639 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 724840595 and 724840604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (724841639) 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, 5409192 + ... + 5409325.

It is an arithmetic number, because the mean of its divisors is an integer number (183914806).

Almost surely, 2^724840639 is an apocalyptic number.

724840639 is a deficient number, since it is larger than the sum of its proper divisors (10818585).

724840639 is a wasteful number, since it uses less digits than its factorization.

724840639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10818584.

The product of its (nonzero) digits is 290304, while the sum is 43.

The square root of 724840639 is about 26922.8646135585. The cubic root of 724840639 is about 898.2850630948.

The spelling of 724840639 in words is "seven hundred twenty-four million, eight hundred forty thousand, six hundred thirty-nine".