21686805520050 has 96 divisors (see below), whose sum is σ = 58674013283520. Its totient is φ = 5257286726400.

The previous prime is 21686805519991. The next prime is 21686805520057. The reversal of 21686805520050 is 5002550868612.

It is not an unprimeable number, because it can be changed into a prime (21686805520057) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 87017016 + ... + 87265884.

It is an arithmetic number, because the mean of its divisors is an integer number (611187638370).

Almost surely, 2^{21686805520050} is an apocalyptic number.

21686805520050 is an abundant number, since it is smaller than the sum of its proper divisors (36987207763470).

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

21686805520050 is a wasteful number, since it uses less digits than its factorization.

21686805520050 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 301708 (or 301703 counting only the distinct ones).

The product of its (nonzero) digits is 1152000, while the sum is 48.

The spelling of 21686805520050 in words is "twenty-one trillion, six hundred eighty-six billion, eight hundred five million, five hundred twenty thousand, fifty".