320689440 has 144 divisors (see below), whose sum is σ = 1108598400. Its totient is φ = 84404736.

The previous prime is 320689433. The next prime is 320689459. The reversal of 320689440 is 44986023.

It is a happy number.

320689440 is a `hidden beast` number, since 3 + 206 + 8 + 9 + 440 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 320689395 and 320689404.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 112351 + ... + 115169.

It is an arithmetic number, because the mean of its divisors is an integer number (7698600).

Almost surely, 2^320689440 is an apocalyptic number.

320689440 is a gapful number since it is divisible by the number (30) 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 320689440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (554299200).

320689440 is an abundant number, since it is smaller than the sum of its proper divisors (787908960).

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

320689440 is a wasteful number, since it uses less digits than its factorization.

320689440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2919 (or 2908 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 320689440 is about 17907.8038854573. The cubic root of 320689440 is about 684.4812454054.

The spelling of 320689440 in words is "three hundred twenty million, six hundred eighty-nine thousand, four hundred forty".