21424317 has 8 divisors (see below), whose sum is σ = 29487360. Its totient is φ = 13822080.

The previous prime is 21424313. The next prime is 21424327. The reversal of 21424317 is 71342412.

It is a happy number.

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

It is not a de Polignac number, because 21424317 - 2² = 21424313 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21424313) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 115092 + ... + 115277.

It is an arithmetic number, because the mean of its divisors is an integer number (3685920).

Almost surely, 2^21424317 is an apocalyptic number.

It is an amenable number.

21424317 is a deficient number, since it is larger than the sum of its proper divisors (8063043).

21424317 is a wasteful number, since it uses less digits than its factorization.

21424317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230403.

The product of its digits is 1344, while the sum is 24.

The square root of 21424317 is about 4628.6409452452. The cubic root of 21424317 is about 277.7382289947.

Adding to 21424317 its reverse (71342412), we get a palindrome (92766729).

It can be divided in two parts, 214 and 24317, that added together give a triangular number (24531 = T₂₂₁).

The spelling of 21424317 in words is "twenty-one million, four hundred twenty-four thousand, three hundred seventeen".