720004421 has 4 divisors (see below), whose sum is σ = 735323712. Its totient is φ = 704685132.

The previous prime is 720004399. The next prime is 720004447. The reversal of 720004421 is 124400027.

720004421 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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-720004421 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 720004393 and 720004402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (720004471) 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, 7659575 + ... + 7659668.

It is an arithmetic number, because the mean of its divisors is an integer number (183830928).

Almost surely, 2^720004421 is an apocalyptic number.

It is an amenable number.

720004421 is a deficient number, since it is larger than the sum of its proper divisors (15319291).

720004421 is a wasteful number, since it uses less digits than its factorization.

720004421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15319290.

The product of its (nonzero) digits is 448, while the sum is 20.

The square root of 720004421 is about 26832.8981103421. The cubic root of 720004421 is about 896.2827837790.

Adding to 720004421 its reverse (124400027), we get a palindrome (844404448).

The spelling of 720004421 in words is "seven hundred twenty million, four thousand, four hundred twenty-one".