405728 has 24 divisors (see below), whose sum is σ = 826560. Its totient is φ = 195840.

The previous prime is 405719. The next prime is 405731. The reversal of 405728 is 827504.

It is a plaindrome in base 13.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 405697 and 405706.

It is a congruent number.

It is an unprimeable number.

405728 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 788 + ... + 1196.

It is an arithmetic number, because the mean of its divisors is an integer number (34440).

2⁴⁰⁵⁷²⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 405728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (413280).

405728 is an abundant number, since it is smaller than the sum of its proper divisors (420832).

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

405728 is a wasteful number, since it uses less digits than its factorization.

405728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 450 (or 442 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 26.

The square root of 405728 is about 636.9678170834. The cubic root of 405728 is about 74.0306666176.

The spelling of 405728 in words is "four hundred five thousand, seven hundred twenty-eight".