636321 has 16 divisors (see below), whose sum is σ = 980864. Its totient is φ = 359424.

The previous prime is 636319. The next prime is 636331. The reversal of 636321 is 123636.

636321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 636321 - 2¹ = 636319 is a prime.

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

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (636301) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3201 + ... + 3393.

It is an arithmetic number, because the mean of its divisors is an integer number (61304).

2⁶³⁶³²¹ is an apocalyptic number.

It is an amenable number.

636321 is a deficient number, since it is larger than the sum of its proper divisors (344543).

636321 is a wasteful number, since it uses less digits than its factorization.

636321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 360.

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

The square root of 636321 is about 797.6973110146. The cubic root of 636321 is about 86.0119417346.

Adding to 636321 its reverse (123636), we get a palindrome (759957).

The spelling of 636321 in words is "six hundred thirty-six thousand, three hundred twenty-one".