320521320 has 128 divisors (see below), whose sum is σ = 1221062400. Its totient is φ = 73260288.

The previous prime is 320521291. The next prime is 320521321. The reversal of 320521320 is 23125023.

320521320 is a `hidden beast` number, since 320 + 5 + 21 + 320 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 320521293 and 320521302.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (320521321) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13639 + ... + 28758.

It is an arithmetic number, because the mean of its divisors is an integer number (9539550).

Almost surely, 2^320521320 is an apocalyptic number.

320521320 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

320521320 is an abundant number, since it is smaller than the sum of its proper divisors (900541080).

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

320521320 is a wasteful number, since it uses less digits than its factorization.

320521320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42424 (or 42414 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 18.

The square root of 320521320 is about 17903.1092271706. The cubic root of 320521320 is about 684.3616124234.

Adding to 320521320 its reverse (23125023), we get a palindrome (343646343).

The spelling of 320521320 in words is "three hundred twenty million, five hundred twenty-one thousand, three hundred twenty".