21216361566000 has 320 divisors, whose sum is σ = 69611074356096. Its totient is φ = 5557888512000.

The previous prime is 21216361565929. The next prime is 21216361566053. The reversal of 21216361566000 is 66516361212.

It is a self number, because there is not a number n which added to its sum of digits gives 21216361566000.

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 63 ways as a sum of consecutive naturals, for example, 291665634 + ... + 291738366.

Almost surely, 2^{21216361566000} is an apocalyptic number.

21216361566000 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 21216361566000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34805537178048).

21216361566000 is an abundant number, since it is smaller than the sum of its proper divisors (48394712790096).

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

21216361566000 is a wasteful number, since it uses less digits than its factorization.

21216361566000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73617 (or 73601 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 39.

The spelling of 21216361566000 in words is "twenty-one trillion, two hundred sixteen billion, three hundred sixty-one million, five hundred sixty-six thousand".