321636 has 36 divisors (see below), whose sum is σ = 874608. Its totient is φ = 91728.

The previous prime is 321631. The next prime is 321647. The reversal of 321636 is 636123.

It is a Harshad number since it is a multiple of its sum of digits (21).

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

It is an alternating number because its digits alternate between odd and even.

It is a nialpdrome in base 14.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 321636.

It is not an unprimeable number, because it can be changed into a prime (321631) by changing a digit.

321636 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 315 + ... + 861.

2³²¹⁶³⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 321636, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (437304).

321636 is an abundant number, since it is smaller than the sum of its proper divisors (552972).

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

321636 is a wasteful number, since it uses less digits than its factorization.

321636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 568 (or 559 counting only the distinct ones).

The product of its digits is 648, while the sum is 21.

The square root of 321636 is about 567.1296148148. The cubic root of 321636 is about 68.5154031463.

Adding to 321636 its reverse (636123), we get a palindrome (957759).

The spelling of 321636 in words is "three hundred twenty-one thousand, six hundred thirty-six".