405421728 has 96 divisors (see below), whose sum is σ = 1101469824. Its totient is φ = 130470912.

The previous prime is 405421721. The next prime is 405421733. The reversal of 405421728 is 827124504.

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (405421721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 557301 + ... + 558027.

It is an arithmetic number, because the mean of its divisors is an integer number (11473644).

Almost surely, 2^405421728 is an apocalyptic number.

405421728 is a gapful number since it is divisible by the number (48) 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 405421728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (550734912).

405421728 is an abundant number, since it is smaller than the sum of its proper divisors (696048096).

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

405421728 is a wasteful number, since it uses less digits than its factorization.

405421728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 934 (or 926 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 33.

The square root of 405421728 is about 20135.0869876442. The cubic root of 405421728 is about 740.1203407892.

The spelling of 405421728 in words is "four hundred five million, four hundred twenty-one thousand, seven hundred twenty-eight".