636642000 has 240 divisors, whose sum is σ = 2250422928. Its totient is φ = 167731200.

The previous prime is 636641963. The next prime is 636642007. The reversal of 636642000 is 246636.

636642000 is a `hidden beast` number, since 636 + 6 + 4 + 20 + 0 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 585833616 + 50808384 = 24204^2 + 7128^2 .

It is a tau number, because it is divible by the number of its divisors (240).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (636642007) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2033844 + ... + 2034156.

Almost surely, 2^636642000 is an apocalyptic number.

636642000 is a gapful number since it is divisible by the number (60) 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 636642000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1125211464).

636642000 is an abundant number, since it is smaller than the sum of its proper divisors (1613780928).

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

636642000 is a wasteful number, since it uses less digits than its factorization.

636642000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 455 (or 436 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 27.

The square root of 636642000 is about 25231.7656932685. The cubic root of 636642000 is about 860.2640256584.

Adding to 636642000 its reverse (246636), we get a palindrome (636888636).

The spelling of 636642000 in words is "six hundred thirty-six million, six hundred forty-two thousand".