636560640 has 288 divisors, whose sum is σ = 2292877440. Its totient is φ = 167215104.

The previous prime is 636560623. The next prime is 636560641. The reversal of 636560640 is 46065636.

636560640 is a `hidden beast` number, since 6 + 3 + 6 + 5 + 6 + 0 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 636560595 and 636560604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (636560641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3905199 + ... + 3905361.

It is an arithmetic number, because the mean of its divisors is an integer number (7961380).

Almost surely, 2^636560640 is an apocalyptic number.

636560640 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 636560640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1146438720).

636560640 is an abundant number, since it is smaller than the sum of its proper divisors (1656316800).

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

636560640 is a wasteful number, since it uses less digits than its factorization.

636560640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306 (or 286 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 36.

The square root of 636560640 is about 25230.1533883566. The cubic root of 636560640 is about 860.2273781324.

The spelling of 636560640 in words is "six hundred thirty-six million, five hundred sixty thousand, six hundred forty".