21216613866712 has 16 divisors (see below), whose sum is σ = 43397619273000. Its totient is φ = 9643915393920.

The previous prime is 21216613866691. The next prime is 21216613866727. The reversal of 21216613866712 is 21766831661212.

It is a self number, because there is not a number n which added to its sum of digits gives 21216613866712.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120548942337 + ... + 120548942512.

Almost surely, 2^{21216613866712} is an apocalyptic number.

21216613866712 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21216613866712 is an abundant number, since it is smaller than the sum of its proper divisors (22181005406288).

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

21216613866712 is a wasteful number, since it uses less digits than its factorization.

21216613866712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241097884866 (or 241097884862 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 52.

The spelling of 21216613866712 in words is "twenty-one trillion, two hundred sixteen billion, six hundred thirteen million, eight hundred sixty-six thousand, seven hundred twelve".