21686834 has 16 divisors (see below), whose sum is σ = 35779968. Its totient is φ = 9795792.

The previous prime is 21686813. The next prime is 21686851. The reversal of 21686834 is 43868612.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7652 + ... + 10095.

It is an arithmetic number, because the mean of its divisors is an integer number (2236248).

Almost surely, 2^21686834 is an apocalyptic number.

21686834 is a deficient number, since it is larger than the sum of its proper divisors (14093134).

21686834 is a wasteful number, since it uses less digits than its factorization.

21686834 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17809.

The product of its digits is 55296, while the sum is 38.

The square root of 21686834 is about 4656.9124964938. The cubic root of 21686834 is about 278.8680233792.

The spelling of 21686834 in words is "twenty-one million, six hundred eighty-six thousand, eight hundred thirty-four".