21571327 has 4 divisors (see below), whose sum is σ = 22706680. Its totient is φ = 20435976.

The previous prime is 21571313. The next prime is 21571339. The reversal of 21571327 is 72317512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21571327 is a prime.

It is a Duffinian number.

It is a plaindrome in base 8.

It is a junction number, because it is equal to n+sod(n) for n = 21571295 and 21571304.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21571357) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 567648 + ... + 567685.

It is an arithmetic number, because the mean of its divisors is an integer number (5676670).

Almost surely, 2^21571327 is an apocalyptic number.

21571327 is the 2682-nd hex number.

21571327 is a deficient number, since it is larger than the sum of its proper divisors (1135353).

21571327 is a wasteful number, since it uses less digits than its factorization.

21571327 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1135352.

The product of its digits is 2940, while the sum is 28.

The square root of 21571327 is about 4644.4942674095. The cubic root of 21571327 is about 278.3720455634.

Adding to 21571327 its reverse (72317512), we get a palindrome (93888839).

The spelling of 21571327 in words is "twenty-one million, five hundred seventy-one thousand, three hundred twenty-seven".