321201664 has 160 divisors (see below), whose sum is σ = 785664000. Its totient is φ = 130959360.

The previous prime is 321201659. The next prime is 321201719. The reversal of 321201664 is 466102123.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5444067 + ... + 5444125.

It is an arithmetic number, because the mean of its divisors is an integer number (4910400).

Almost surely, 2^321201664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 321201664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (392832000).

321201664 is an abundant number, since it is smaller than the sum of its proper divisors (464462336).

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

321201664 is an frugal number, since it uses more digits than its factorization.

321201664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129 (or 99 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 321201664 is about 17922.0998769675. The cubic root of 321201664 is about 684.8454827566.

Adding to 321201664 its reverse (466102123), we get a palindrome (787303787).

The spelling of 321201664 in words is "three hundred twenty-one million, two hundred one thousand, six hundred sixty-four".