321891072 has 72 divisors (see below), whose sum is σ = 893996544. Its totient is φ = 102626304.

The previous prime is 321891071. The next prime is 321891113. The reversal of 321891072 is 270198123.

It is a super-2 number, since 2×321891072² = 207227724466618368, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (321891071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8553 + ... + 26775.

Almost surely, 2^321891072 is an apocalyptic number.

321891072 is a gapful number since it is divisible by the number (32) 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 321891072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (446998272).

321891072 is an abundant number, since it is smaller than the sum of its proper divisors (572105472).

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

321891072 is a wasteful number, since it uses less digits than its factorization.

321891072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18265 (or 18251 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 321891072 is about 17941.3230281381. The cubic root of 321891072 is about 685.3351030586.

The spelling of 321891072 in words is "three hundred twenty-one million, eight hundred ninety-one thousand, seventy-two".