21781355904000 has 3168 divisors, whose sum is σ = 102163023286272. Its totient is φ = 4330782720000.

The previous prime is 21781355903977. The next prime is 21781355904029. The reversal of 21781355904000 is 40955318712.

21781355904000 is a `hidden beast` number, since 2 + 1 + 7 + 8 + 13 + 5 + 590 + 40 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (3168).

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 287 ways as a sum of consecutive naturals, for example, 244734335956 + ... + 244734336044.

Almost surely, 2^{21781355904000} is an apocalyptic number.

21781355904000 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 21781355904000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51081511643136).

21781355904000 is an abundant number, since it is smaller than the sum of its proper divisors (80381667382272).

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

21781355904000 is a wasteful number, since it uses less digits than its factorization.

21781355904000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 268 (or 148 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 45.

The spelling of 21781355904000 in words is "twenty-one trillion, seven hundred eighty-one billion, three hundred fifty-five million, nine hundred four thousand".