320013520 has 20 divisors (see below), whose sum is σ = 744031620. Its totient is φ = 128005376.

The previous prime is 320013517. The next prime is 320013539. The reversal of 320013520 is 25310023.

It can be written as a sum of positive squares in 2 ways, for example, as 254338704 + 65674816 = 15948^2 + 8104^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 320013494 and 320013503.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2000005 + ... + 2000164.

It is an arithmetic number, because the mean of its divisors is an integer number (37201581).

Almost surely, 2^320013520 is an apocalyptic number.

It is an amenable number.

320013520 is an abundant number, since it is smaller than the sum of its proper divisors (424018100).

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

320013520 is a wasteful number, since it uses less digits than its factorization.

320013520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4000182 (or 4000176 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 16.

The square root of 320013520 is about 17888.9217114951. The cubic root of 320013520 is about 684.0000113995. Note that the first 4 decimals are identical.

Subtracting from 320013520 its sum of digits (16), we obtain a cube (320013504 = 684³).

Adding to 320013520 its reverse (25310023), we get a palindrome (345323543).

The spelling of 320013520 in words is "three hundred twenty million, thirteen thousand, five hundred twenty".