21217984196892 has 48 divisors (see below), whose sum is σ = 56763224673792. Its totient is φ = 6042788326080.

The previous prime is 21217984196797. The next prime is 21217984196951. The reversal of 21217984196892 is 29869148971212.

It is a happy number.

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 15 ways as a sum of consecutive naturals, for example, 406075243 + ... + 406127490.

It is an arithmetic number, because the mean of its divisors is an integer number (1182567180704).

Almost surely, 2^{21217984196892} is an apocalyptic number.

It is an amenable number.

21217984196892 is an abundant number, since it is smaller than the sum of its proper divisors (35545240476900).

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

21217984196892 is a wasteful number, since it uses less digits than its factorization.

21217984196892 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 812203058 (or 812203056 counting only the distinct ones).

The product of its digits is 62705664, while the sum is 69.

The spelling of 21217984196892 in words is "twenty-one trillion, two hundred seventeen billion, nine hundred eighty-four million, one hundred ninety-six thousand, eight hundred ninety-two".