20949904800 has 864 divisors, whose sum is σ = 85272917184. Its totient is φ = 4976640000.

The previous prime is 20949904771. The next prime is 20949904817. The reversal of 20949904800 is 840994902.

It is a tau number, because it is divible by the number of its divisors (864).

It is a super-2 number, since 2×20949904800² (a number of 21 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 207424750 + ... + 207424850.

It is an arithmetic number, because the mean of its divisors is an integer number (98695506).

Almost surely, 2^20949904800 is an apocalyptic number.

20949904800 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 20949904800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42636458592).

20949904800 is an abundant number, since it is smaller than the sum of its proper divisors (64323012384).

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

20949904800 is a wasteful number, since it uses less digits than its factorization.

20949904800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244 (or 219 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 45.

The spelling of 20949904800 in words is "twenty billion, nine hundred forty-nine million, nine hundred four thousand, eight hundred".