21191298813216 has 144 divisors (see below), whose sum is σ = 71899049688480. Its totient is φ = 6054656791680.

The previous prime is 21191298813151. The next prime is 21191298813229. The reversal of 21191298813216 is 61231889219112.

21191298813216 is a `hidden beast` number, since 2 + 119 + 129 + 8 + 81 + 321 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×21191298813216² (a number of 27 digits) contains 22 as substring.

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

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 250232830 + ... + 250317501.

It is an arithmetic number, because the mean of its divisors is an integer number (499298956170).

Almost surely, 2^{21191298813216} is an apocalyptic number.

It is an amenable number.

21191298813216 is an abundant number, since it is smaller than the sum of its proper divisors (50707750875264).

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

21191298813216 is a wasteful number, since it uses less digits than its factorization.

21191298813216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 500550364 (or 500550343 counting only the distinct ones).

The product of its digits is 746496, while the sum is 54.

The spelling of 21191298813216 in words is "twenty-one trillion, one hundred ninety-one billion, two hundred ninety-eight million, eight hundred thirteen thousand, two hundred sixteen".