21478730181600 has 288 divisors, whose sum is σ = 70136480915424. Its totient is φ = 5709400473600.

The previous prime is 21478730181577. The next prime is 21478730181637. The reversal of 21478730181600 is 618103787412.

It is a super-2 number, since 2×21478730181600² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 21478730181600.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 1142901804 + ... + 1142920596.

It is an arithmetic number, because the mean of its divisors is an integer number (243529447623).

Almost surely, 2^{21478730181600} is an apocalyptic number.

21478730181600 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 21478730181600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35068240457712).

21478730181600 is an abundant number, since it is smaller than the sum of its proper divisors (48657750733824).

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

21478730181600 is a wasteful number, since it uses less digits than its factorization.

21478730181600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20310 (or 20297 counting only the distinct ones).

The product of its (nonzero) digits is 451584, while the sum is 48.

The spelling of 21478730181600 in words is "twenty-one trillion, four hundred seventy-eight billion, seven hundred thirty million, one hundred eighty-one thousand, six hundred".