636636 has 96 divisors (see below), whose sum is σ = 2032128. Its totient is φ = 149760.

The previous prime is 636631. The next prime is 636653.

636636 is nontrivially palindromic in base 10.

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

It is a plaindrome in base 8.

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 636636.

It is not an unprimeable number, because it can be changed into a prime (636631) by changing a digit.

636636 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 31 ways as a sum of consecutive naturals, for example, 11986 + ... + 12038.

It is an arithmetic number, because the mean of its divisors is an integer number (21168).

2⁶³⁶⁶³⁶ is an apocalyptic number.

636636 is a gapful number since it is divisible by the number (66) 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 636636, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1016064).

636636 is an abundant number, since it is smaller than the sum of its proper divisors (1395492).

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

636636 is a wasteful number, since it uses less digits than its factorization.

636636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91 (or 89 counting only the distinct ones).

The product of its digits is 11664, while the sum is 30.

The square root of 636636 is about 797.8947298986. The cubic root of 636636 is about 86.0261323145.

The spelling of 636636 in words is "six hundred thirty-six thousand, six hundred thirty-six".