20009721600 has 1080 divisors, whose sum is σ = 84184143120. Its totient is φ = 4683571200.

The previous prime is 20009721583. The next prime is 20009721607. The reversal of 20009721600 is 612790002.

It is a tau number, because it is divible by the number of its divisors (1080).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20009721607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 689990386 + ... + 689990414.

Almost surely, 2^20009721600 is an apocalyptic number.

20009721600 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 20009721600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42092071560).

20009721600 is an abundant number, since it is smaller than the sum of its proper divisors (64174421520).

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

20009721600 is an equidigital number, since it uses as much as digits as its factorization.

20009721600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100 (or 50 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The spelling of 20009721600 in words is "twenty billion, nine million, seven hundred twenty-one thousand, six hundred".