320621640 has 64 divisors (see below), whose sum is σ = 985340160. Its totient is φ = 83412480.

The previous prime is 320621629. The next prime is 320621641. The reversal of 320621640 is 46126023.

320621640 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 320621640.

It is not an unprimeable number, because it can be changed into a prime (320621641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27664 + ... + 37503.

It is an arithmetic number, because the mean of its divisors is an integer number (15395940).

Almost surely, 2^320621640 is an apocalyptic number.

320621640 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

320621640 is an abundant number, since it is smaller than the sum of its proper divisors (664718520).

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

320621640 is a wasteful number, since it uses less digits than its factorization.

320621640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65222 (or 65218 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 320621640 is about 17905.9107559487. The cubic root of 320621640 is about 684.4330044454.

Adding to 320621640 its reverse (46126023), we get a palindrome (366747663).

The spelling of 320621640 in words is "three hundred twenty million, six hundred twenty-one thousand, six hundred forty".