636600640 has 112 divisors (see below), whose sum is σ = 1645901712. Its totient is φ = 233127936.

The previous prime is 636600631. The next prime is 636600641. The reversal of 636600640 is 46006636.

It can be written as a sum of positive squares in 8 ways, for example, as 151191616 + 485409024 = 12296^2 + 22032^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (636600641) 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, 569362 + ... + 570478.

It is an arithmetic number, because the mean of its divisors is an integer number (14695551).

Almost surely, 2^636600640 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 636600640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (822950856).

636600640 is an abundant number, since it is smaller than the sum of its proper divisors (1009301072).

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

636600640 is a wasteful number, since it uses less digits than its factorization.

636600640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1284 (or 1274 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 31.

The square root of 636600640 is about 25230.9460781795. The cubic root of 636600640 is about 860.2453959887.

The spelling of 636600640 in words is "six hundred thirty-six million, six hundred thousand, six hundred forty".