21664314 has 64 divisors (see below), whose sum is σ = 56544000. Its totient is φ = 6018624.

The previous prime is 21664297. The next prime is 21664327. The reversal of 21664314 is 41346612.

21664314 is a `hidden beast` number, since 2 + 1 + 6 + 643 + 14 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 13212 + ... + 14760.

It is an arithmetic number, because the mean of its divisors is an integer number (883500).

Almost surely, 2^21664314 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21664314, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28272000).

21664314 is an abundant number, since it is smaller than the sum of its proper divisors (34879686).

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

21664314 is a wasteful number, since it uses less digits than its factorization.

21664314 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1604 (or 1598 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 21664314 is about 4654.4939574566. The cubic root of 21664314 is about 278.7714627511.

The spelling of 21664314 in words is "twenty-one million, six hundred sixty-four thousand, three hundred fourteen".