321012720 has 360 divisors, whose sum is σ = 1304385264. Its totient is φ = 73156608.

The previous prime is 321012701. The next prime is 321012761. The reversal of 321012720 is 27210123.

It is a tau number, because it is divible by the number of its divisors (360).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 321012693 and 321012702.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 952392 + ... + 952728.

Almost surely, 2^321012720 is an apocalyptic number.

321012720 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 321012720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (652192632).

321012720 is an abundant number, since it is smaller than the sum of its proper divisors (983372544).

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

321012720 is a wasteful number, since it uses less digits than its factorization.

321012720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 379 (or 354 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 321012720 is about 17916.8278442363. The cubic root of 321012720 is about 684.7111716783.

Adding to 321012720 its reverse (27210123), we get a palindrome (348222843).

The spelling of 321012720 in words is "three hundred twenty-one million, twelve thousand, seven hundred twenty".