321661326 has 48 divisors (see below), whose sum is σ = 751418496. Its totient is φ = 89921904.

The previous prime is 321661321. The next prime is 321661331. The reversal of 321661326 is 623166123.

It is an interprime number because it is at equal distance from previous prime (321661321) and next prime (321661331).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 321661293 and 321661302.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (321661321) 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 23 ways as a sum of consecutive naturals, for example, 91045 + ... + 94511.

It is an arithmetic number, because the mean of its divisors is an integer number (15654552).

Almost surely, 2^321661326 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 321661326, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (375709248).

321661326 is an abundant number, since it is smaller than the sum of its proper divisors (429757170).

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

321661326 is a wasteful number, since it uses less digits than its factorization.

321661326 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3573 (or 3526 counting only the distinct ones).

The product of its digits is 7776, while the sum is 30.

The square root of 321661326 is about 17934.9191801915. The cubic root of 321661326 is about 685.1720142715.

The spelling of 321661326 in words is "three hundred twenty-one million, six hundred sixty-one thousand, three hundred twenty-six".