21438778032000 has 3072 divisors, whose sum is σ = 98583928934400. Its totient is φ = 4521775104000.

The previous prime is 21438778031941. The next prime is 21438778032031. The reversal of 21438778032000 is 23087783412.

21438778032000 is a `hidden beast` number, since 2 + 1 + 438 + 7 + 7 + 8 + 0 + 3 + 200 + 0 = 666.

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 pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 18153071410 + ... + 18153072590.

It is an arithmetic number, because the mean of its divisors is an integer number (32091122700).

Almost surely, 2^{21438778032000} is an apocalyptic number.

21438778032000 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 21438778032000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49291964467200).

21438778032000 is an abundant number, since it is smaller than the sum of its proper divisors (77145150902400).

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

21438778032000 is a wasteful number, since it uses less digits than its factorization.

21438778032000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1284 (or 1250 counting only the distinct ones).

The product of its (nonzero) digits is 451584, while the sum is 45.

The spelling of 21438778032000 in words is "twenty-one trillion, four hundred thirty-eight billion, seven hundred seventy-eight million, thirty-two thousand".