21043156616784 has 160 divisors (see below), whose sum is σ = 61244176947200. Its totient is φ = 6916591503360.

The previous prime is 21043156616767. The next prime is 21043156616809. The reversal of 21043156616784 is 48761665134012.

21043156616784 is a `hidden beast` number, since 2 + 1 + 0 + 4 + 3 + 1 + 566 + 1 + 6 + 78 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 21043156616784.

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 31 ways as a sum of consecutive naturals, for example, 131078004 + ... + 131238444.

It is an arithmetic number, because the mean of its divisors is an integer number (382776105920).

Almost surely, 2^{21043156616784} is an apocalyptic number.

21043156616784 is a gapful number since it is divisible by the number (24) 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 21043156616784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30622088473600).

21043156616784 is an abundant number, since it is smaller than the sum of its proper divisors (40201020330416).

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

21043156616784 is a wasteful number, since it uses less digits than its factorization.

21043156616784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164690 (or 164678 counting only the distinct ones).

The product of its (nonzero) digits is 5806080, while the sum is 54.

The spelling of 21043156616784 in words is "twenty-one trillion, forty-three billion, one hundred fifty-six million, six hundred sixteen thousand, seven hundred eighty-four".