21686848 has 14 divisors (see below), whose sum is σ = 43034966. Its totient is φ = 10843392.

The previous prime is 21686813. The next prime is 21686851. The reversal of 21686848 is 84868612.

It can be written as a sum of positive squares in only one way, i.e., 21603904 + 82944 = 4648^2 + 288^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 169365 + ... + 169492.

Almost surely, 2^21686848 is an apocalyptic number.

It is an amenable number.

21686848 is a deficient number, since it is larger than the sum of its proper divisors (21348118).

21686848 is an equidigital number, since it uses as much as digits as its factorization.

21686848 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 338869 (or 338859 counting only the distinct ones).

The product of its digits is 147456, while the sum is 43.

The square root of 21686848 is about 4656.9139996354. The cubic root of 21686848 is about 278.8680833872.

The spelling of 21686848 in words is "twenty-one million, six hundred eighty-six thousand, eight hundred forty-eight".