21686534219 has 12 divisors (see below), whose sum is σ = 25842492648. Its totient is φ = 18135079200.

The previous prime is 21686534209. The next prime is 21686534249. The reversal of 21686534219 is 91243568612.

It is a de Polignac number, because none of the positive numbers 2^k-21686534219 is a prime.

It is a super-2 number, since 2×21686534219² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21686534209) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5395337 + ... + 5399354.

It is an arithmetic number, because the mean of its divisors is an integer number (2153541054).

Almost surely, 2^21686534219 is an apocalyptic number.

21686534219 is a deficient number, since it is larger than the sum of its proper divisors (4155958429).

21686534219 is a wasteful number, since it uses less digits than its factorization.

21686534219 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10794746 (or 10794739 counting only the distinct ones).

The product of its digits is 622080, while the sum is 47.

The spelling of 21686534219 in words is "twenty-one billion, six hundred eighty-six million, five hundred thirty-four thousand, two hundred nineteen".