321628320 has 480 divisors, whose sum is σ = 1290909312. Its totient is φ = 74815488.

The previous prime is 321628283. The next prime is 321628337. The reversal of 321628320 is 23826123.

321628320 is a `hidden beast` number, since 3 + 2 + 1 + 628 + 32 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 3874999 + ... + 3875081.

Almost surely, 2^321628320 is an apocalyptic number.

321628320 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 321628320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (645454656).

321628320 is an abundant number, since it is smaller than the sum of its proper divisors (969280992).

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

321628320 is a wasteful number, since it uses less digits than its factorization.

321628320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146 (or 129 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 321628320 is about 17933.9989963198. The cubic root of 321628320 is about 685.1485780679.

The spelling of 321628320 in words is "three hundred twenty-one million, six hundred twenty-eight thousand, three hundred twenty".