728398440 has 512 divisors, whose sum is σ = 3193344000. Its totient is φ = 143078400.

The previous prime is 728398417. The next prime is 728398493. The reversal of 728398440 is 44893827.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1579810 + ... + 1580270.

It is an arithmetic number, because the mean of its divisors is an integer number (6237000).

Almost surely, 2^728398440 is an apocalyptic number.

728398440 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 728398440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1596672000).

728398440 is an abundant number, since it is smaller than the sum of its proper divisors (2464945560).

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

728398440 is a wasteful number, since it uses less digits than its factorization.

728398440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 518 (or 508 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 45.

The square root of 728398440 is about 26988.8577009106. The cubic root of 728398440 is about 899.7523763202.

The spelling of 728398440 in words is "seven hundred twenty-eight million, three hundred ninety-eight thousand, four hundred forty".