20281718400 has 384 divisors, whose sum is σ = 69619651200. Its totient is φ = 5183324160.

The previous prime is 20281718357. The next prime is 20281718441. The reversal of 20281718400 is 481718202.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (384).

It is a super-2 number, since 2×20281718400² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 73219062 + ... + 73219338.

It is an arithmetic number, because the mean of its divisors is an integer number (181301175).

Almost surely, 2^20281718400 is an apocalyptic number.

20281718400 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 20281718400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34809825600).

20281718400 is an abundant number, since it is smaller than the sum of its proper divisors (49337932800).

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

20281718400 is a wasteful number, since it uses less digits than its factorization.

20281718400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 596 (or 579 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 33.

The spelling of 20281718400 in words is "twenty billion, two hundred eighty-one million, seven hundred eighteen thousand, four hundred".