20636640000 has 720 divisors, whose sum is σ = 81031436640. Its totient is φ = 5160960000.

The previous prime is 20636639987. The next prime is 20636640121. The reversal of 20636640000 is 4663602.

20636640000 is a `hidden beast` number, since 20 + 636 + 6 + 4 + 0 + 0 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

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 79 ways as a sum of consecutive naturals, for example, 73439860 + ... + 73440140.

It is an arithmetic number, because the mean of its divisors is an integer number (112543662).

Almost surely, 2^20636640000 is an apocalyptic number.

20636640000 is a gapful number since it is divisible by the number (20) 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 20636640000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40515718320).

20636640000 is an abundant number, since it is smaller than the sum of its proper divisors (60394796640).

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

20636640000 is an equidigital number, since it uses as much as digits as its factorization.

20636640000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343 (or 308 counting only the distinct ones).

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

The spelling of 20636640000 in words is "twenty billion, six hundred thirty-six million, six hundred forty thousand".