21686334 has 32 divisors (see below), whose sum is σ = 45951360. Its totient is φ = 6804000.

The previous prime is 21686333. The next prime is 21686347. The reversal of 21686334 is 43368612.

It is a junction number, because it is equal to n+sod(n) for n = 21686295 and 21686304.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21686333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20109 + ... + 21159.

It is an arithmetic number, because the mean of its divisors is an integer number (1435980).

Almost surely, 2^21686334 is an apocalyptic number.

21686334 is an abundant number, since it is smaller than the sum of its proper divisors (24265026).

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

21686334 is a wasteful number, since it uses less digits than its factorization.

21686334 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1256.

The product of its digits is 20736, while the sum is 33.

The square root of 21686334 is about 4656.8588125474. The cubic root of 21686334 is about 278.8658802189.

The spelling of 21686334 in words is "twenty-one million, six hundred eighty-six thousand, three hundred thirty-four".