21371317 has 8 divisors (see below), whose sum is σ = 23610240. Its totient is φ = 19181760.

The previous prime is 21371299. The next prime is 21371341. The reversal of 21371317 is 71317312.

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 21371317 - 2²³ = 12982709 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21371291 and 21371300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21371377) 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, 11428 + ... + 13165.

It is an arithmetic number, because the mean of its divisors is an integer number (2951280).

Almost surely, 2^21371317 is an apocalyptic number.

It is an amenable number.

21371317 is a deficient number, since it is larger than the sum of its proper divisors (2238923).

21371317 is a wasteful number, since it uses less digits than its factorization.

21371317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24683.

The product of its digits is 882, while the sum is 25.

The square root of 21371317 is about 4622.9121774051. The cubic root of 21371317 is about 277.5090146681.

Adding to 21371317 its reverse (71317312), we get a palindrome (92688629).

The spelling of 21371317 in words is "twenty-one million, three hundred seventy-one thousand, three hundred seventeen".