12171220727 has 2 divisors, whose sum is σ = 12171220728. Its totient is φ = 12171220726.

The previous prime is 12171220717. The next prime is 12171220729. The reversal of 12171220727 is 72702217121.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 12171220727 - 2⁸ = 12171220471 is a prime.

It is a super-2 number, since 2×12171220727² (a number of 21 digits) contains 22 as substring.

Together with 12171220729, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 12171220693 and 12171220702.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12171220729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6085610363 + 6085610364.

It is an arithmetic number, because the mean of its divisors is an integer number (6085610364).

Almost surely, 2^12171220727 is an apocalyptic number.

12171220727 is a deficient number, since it is larger than the sum of its proper divisors (1).

12171220727 is an equidigital number, since it uses as much as digits as its factorization.

12171220727 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5488, while the sum is 32.

Adding to 12171220727 its reverse (72702217121), we get a palindrome (84873437848).

The spelling of 12171220727 in words is "twelve billion, one hundred seventy-one million, two hundred twenty thousand, seven hundred twenty-seven".