21643645650312 has 384 divisors, whose sum is σ = 65864984371200. Its totient is φ = 5902564147200.

The previous prime is 21643645650311. The next prime is 21643645650349. The reversal of 21643645650312 is 21305654634612.

It is not an unprimeable number, because it can be changed into a prime (21643645650311) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1939562989 + ... + 1939574147.

It is an arithmetic number, because the mean of its divisors is an integer number (171523396800).

Almost surely, 2^{21643645650312} 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 21643645650312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32932492185600).

21643645650312 is an abundant number, since it is smaller than the sum of its proper divisors (44221338720888).

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

21643645650312 is a wasteful number, since it uses less digits than its factorization.

21643645650312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11937 (or 11926 counting only the distinct ones).

The product of its (nonzero) digits is 3110400, while the sum is 48.

The spelling of 21643645650312 in words is "twenty-one trillion, six hundred forty-three billion, six hundred forty-five million, six hundred fifty thousand, three hundred twelve".