320400432 has 120 divisors (see below), whose sum is σ = 993120960. Its totient is φ = 95610240.

The previous prime is 320400413. The next prime is 320400433. The reversal of 320400432 is 234004023.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (320400433) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 104619 + ... + 107637.

It is an arithmetic number, because the mean of its divisors is an integer number (8276008).

Almost surely, 2^320400432 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 320400432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (496560480).

320400432 is an abundant number, since it is smaller than the sum of its proper divisors (672720528).

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

320400432 is a wasteful number, since it uses less digits than its factorization.

320400432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3111 (or 3102 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 18.

The square root of 320400432 is about 17899.7327354349. The cubic root of 320400432 is about 684.2755635352.

Adding to 320400432 its reverse (234004023), we get a palindrome (554404455).

The spelling of 320400432 in words is "three hundred twenty million, four hundred thousand, four hundred thirty-two".