321916 has 12 divisors (see below), whose sum is σ = 643888. Its totient is φ = 137952.

The previous prime is 321911. The next prime is 321947. The reversal of 321916 is 619123.

321916 = T₇₈ + T₇₉ + ... + T₁₃₃.

321916 is an admirable number.

It is a super-2 number, since 2×321916² = 207259822112, which contains 22 as substring.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 321916.

It is not an unprimeable number, because it can be changed into a prime (321911) by changing a digit.

321916 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5721 + ... + 5776.

2³²¹⁹¹⁶ is an apocalyptic number.

It is an amenable number.

321916 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

321916 is a wasteful number, since it uses less digits than its factorization.

321916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11508 (or 11506 counting only the distinct ones).

The product of its digits is 324, while the sum is 22.

The square root of 321916 is about 567.3764182622. The cubic root of 321916 is about 68.5352793922.

The spelling of 321916 in words is "three hundred twenty-one thousand, nine hundred sixteen".