21671327 has 2 divisors, whose sum is σ = 21671328. Its totient is φ = 21671326.

The previous prime is 21671297. The next prime is 21671333. The reversal of 21671327 is 72317612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21671327 - 2¹⁰ = 21670303 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21671327.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21671347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10835663 + 10835664.

It is an arithmetic number, because the mean of its divisors is an integer number (10835664).

Almost surely, 2^21671327 is an apocalyptic number.

21671327 is a deficient number, since it is larger than the sum of its proper divisors (1).

21671327 is an equidigital number, since it uses as much as digits as its factorization.

21671327 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3528, while the sum is 29.

The square root of 21671327 is about 4655.2472544431. The cubic root of 21671327 is about 278.8015400686.

Adding to 21671327 its reverse (72317612), we get a palindrome (93988939).

The spelling of 21671327 in words is "twenty-one million, six hundred seventy-one thousand, three hundred twenty-seven".