20649585600 has 252 divisors, whose sum is σ = 83878698384. Its totient is φ = 4719882240.

The previous prime is 20649585599. The next prime is 20649585601. The reversal of 20649585600 is 658594602.

20649585600 is a `hidden beast` number, since 2 + 0 + 6 + 4 + 9 + 585 + 60 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (20649585599) and next prime (20649585601).

It is a tau number, because it is divible by the number of its divisors (252).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20649585601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1629 + ... + 203228.

Almost surely, 2^20649585600 is an apocalyptic number.

20649585600 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 20649585600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41939349192).

20649585600 is an abundant number, since it is smaller than the sum of its proper divisors (63229112784).

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

20649585600 is a wasteful number, since it uses less digits than its factorization.

20649585600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204892 (or 204874 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 45.

The spelling of 20649585600 in words is "twenty billion, six hundred forty-nine million, five hundred eighty-five thousand, six hundred".