724428 has 18 divisors (see below), whose sum is σ = 1831284. Its totient is φ = 241464.

The previous prime is 724403. The next prime is 724433. The reversal of 724428 is 824427.

724428 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (18).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10026 + ... + 10097.

It is an arithmetic number, because the mean of its divisors is an integer number (101738).

2⁷²⁴⁴²⁸ is an apocalyptic number.

It is an amenable number.

724428 is an abundant number, since it is smaller than the sum of its proper divisors (1106856).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

724428 is a wasteful number, since it uses less digits than its factorization.

724428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20133 (or 20128 counting only the distinct ones).

The product of its digits is 3584, while the sum is 27.

The square root of 724428 is about 851.1333620532. The cubic root of 724428 is about 89.8114571454.

Subtracting 724428 from its reverse (824427), we obtain a palindrome (99999).

The spelling of 724428 in words is "seven hundred twenty-four thousand, four hundred twenty-eight".