21688348 has 24 divisors (see below), whose sum is σ = 43585920. Its totient is φ = 9339120.

The previous prime is 21688343. The next prime is 21688391. The reversal of 21688348 is 84388612.

It is a self number, because there is not a number n which added to its sum of digits gives 21688348.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21688343) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12136 + ... + 13807.

It is an arithmetic number, because the mean of its divisors is an integer number (1816080).

Almost surely, 2^21688348 is an apocalyptic number.

It is an amenable number.

21688348 is an abundant number, since it is smaller than the sum of its proper divisors (21897572).

21688348 is a wasteful number, since it uses less digits than its factorization.

21688348 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25977 (or 25975 counting only the distinct ones).

The product of its digits is 73728, while the sum is 40.

The square root of 21688348 is about 4657.0750477097. The cubic root of 21688348 is about 278.8745126676.

The spelling of 21688348 in words is "twenty-one million, six hundred eighty-eight thousand, three hundred forty-eight".