21666346624112 has 80 divisors (see below), whose sum is σ = 44972073984000. Its totient is φ = 10081158124032.

The previous prime is 21666346624103. The next prime is 21666346624163. The reversal of 21666346624112 is 21142664366612.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22467908 + ... + 23412380.

It is an arithmetic number, because the mean of its divisors is an integer number (562150924800).

Almost surely, 2^{21666346624112} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21666346624112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22486036992000).

21666346624112 is an abundant number, since it is smaller than the sum of its proper divisors (23305727359888).

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

21666346624112 is a wasteful number, since it uses less digits than its factorization.

21666346624112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 945838 (or 945832 counting only the distinct ones).

The product of its digits is 2985984, while the sum is 50.

The spelling of 21666346624112 in words is "twenty-one trillion, six hundred sixty-six billion, three hundred forty-six million, six hundred twenty-four thousand, one hundred twelve".