21217214 has 8 divisors (see below), whose sum is σ = 32274288. Its totient is φ = 10459120.

The previous prime is 21217199. The next prime is 21217223. The reversal of 21217214 is 41271212.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 74567 + ... + 74850.

It is an arithmetic number, because the mean of its divisors is an integer number (4034286).

Almost surely, 2^21217214 is an apocalyptic number.

21217214 is a deficient number, since it is larger than the sum of its proper divisors (11057074).

21217214 is a wasteful number, since it uses less digits than its factorization.

21217214 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149490.

The product of its digits is 224, while the sum is 20.

The square root of 21217214 is about 4606.2147149259. The cubic root of 21217214 is about 276.8403899179.

Adding to 21217214 its reverse (41271212), we get a palindrome (62488426).

The spelling of 21217214 in words is "twenty-one million, two hundred seventeen thousand, two hundred fourteen".