321279678720 has 2304 divisors, whose sum is σ = 1578394460160. Its totient is φ = 59719680000.

The previous prime is 321279678703. The next prime is 321279678721. The reversal of 321279678720 is 27876972123.

It is a tau number, because it is divible by the number of its divisors (2304).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (321279678721) by changing a digit.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 1279998595 + ... + 1279998845.

It is an arithmetic number, because the mean of its divisors is an integer number (685067040).

Almost surely, 2^321279678720 is an apocalyptic number.

321279678720 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 321279678720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (789197230080).

321279678720 is an abundant number, since it is smaller than the sum of its proper divisors (1257114781440).

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

321279678720 is a wasteful number, since it uses less digits than its factorization.

321279678720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 349 (or 329 counting only the distinct ones).

The product of its (nonzero) digits is 3556224, while the sum is 54.

It can be divided in two parts, 321279 and 678720, that added together give a palindrome (999999).

The spelling of 321279678720 in words is "three hundred twenty-one billion, two hundred seventy-nine million, six hundred seventy-eight thousand, seven hundred twenty".