21256608384000 has 1760 divisors, whose sum is σ = 89414135141760. Its totient is φ = 4974649344000.

The previous prime is 21256608383993. The next prime is 21256608384013. The reversal of 21256608384000 is 48380665212.

21256608384000 is a `hidden beast` number, since 2 + 1 + 2 + 5 + 6 + 608 + 38 + 4 + 0 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1760).

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

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 3307388787 + ... + 3307395213.

It is an arithmetic number, because the mean of its divisors is an integer number (50803485876).

Almost surely, 2^{21256608384000} is an apocalyptic number.

21256608384000 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 21256608384000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44707067570880).

21256608384000 is an abundant number, since it is smaller than the sum of its proper divisors (68157526757760).

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

21256608384000 is a wasteful number, since it uses less digits than its factorization.

21256608384000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6514 (or 6477 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 45.

The spelling of 21256608384000 in words is "twenty-one trillion, two hundred fifty-six billion, six hundred eight million, three hundred eighty-four thousand".