328721520 has 320 divisors, whose sum is σ = 1172496384. Its totient is φ = 75694080.

The previous prime is 328721501. The next prime is 328721531. The reversal of 328721520 is 25127823.

It is a super-2 number, since 2×328721520² = 216115675422220800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2908984 + ... + 2909096.

Almost surely, 2^328721520 is an apocalyptic number.

328721520 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 328721520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (586248192).

328721520 is an abundant number, since it is smaller than the sum of its proper divisors (843774864).

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

328721520 is a wasteful number, since it uses less digits than its factorization.

328721520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200 (or 194 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 328721520 is about 18130.6789723937. The cubic root of 328721520 is about 690.1487601963.

The spelling of 328721520 in words is "three hundred twenty-eight million, seven hundred twenty-one thousand, five hundred twenty".