21688327 has 8 divisors (see below), whose sum is σ = 22507856. Its totient is φ = 20881152.

The previous prime is 21688307. The next prime is 21688343. The reversal of 21688327 is 72388612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21688327 - 2¹¹ = 21686279 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21688307) 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, 568 + ... + 6610.

It is an arithmetic number, because the mean of its divisors is an integer number (2813482).

Almost surely, 2^21688327 is an apocalyptic number.

21688327 is a deficient number, since it is larger than the sum of its proper divisors (819529).

21688327 is an equidigital number, since it uses as much as digits as its factorization.

21688327 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6177.

The product of its digits is 32256, while the sum is 37.

The square root of 21688327 is about 4657.0727930751. The cubic root of 21688327 is about 278.8744226597.

The spelling of 21688327 in words is "twenty-one million, six hundred eighty-eight thousand, three hundred twenty-seven".