728421240 has 64 divisors (see below), whose sum is σ = 2300284800. Its totient is φ = 184021632.

The previous prime is 728421203. The next prime is 728421269. The reversal of 728421240 is 42124827.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 728421198 and 728421207.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 157462 + ... + 162021.

It is an arithmetic number, because the mean of its divisors is an integer number (35941950).

Almost surely, 2^728421240 is an apocalyptic number.

It is an amenable number.

728421240 is an abundant number, since it is smaller than the sum of its proper divisors (1571863560).

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

728421240 is a wasteful number, since it uses less digits than its factorization.

728421240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319516 (or 319512 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 30.

The square root of 728421240 is about 26989.2800941411. The cubic root of 728421240 is about 899.7617641035.

The spelling of 728421240 in words is "seven hundred twenty-eight million, four hundred twenty-one thousand, two hundred forty".