131221202117 has 2 divisors, whose sum is σ = 131221202118. Its totient is φ = 131221202116.

The previous prime is 131221202071. The next prime is 131221202129. The reversal of 131221202117 is 711202122131.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 130674297121 + 546904996 = 361489^2 + 23386^2 .

It is a cyclic number.

It is not a de Polignac number, because 131221202117 - 2¹⁸ = 131220939973 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 131221202092 and 131221202101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (131221202017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65610601058 + 65610601059.

It is an arithmetic number, because the mean of its divisors is an integer number (65610601059).

Almost surely, 2^131221202117 is an apocalyptic number.

It is an amenable number.

131221202117 is a deficient number, since it is larger than the sum of its proper divisors (1).

131221202117 is an equidigital number, since it uses as much as digits as its factorization.

131221202117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 336, while the sum is 23.

Adding to 131221202117 its reverse (711202122131), we get a palindrome (842423324248).

The spelling of 131221202117 in words is "one hundred thirty-one billion, two hundred twenty-one million, two hundred two thousand, one hundred seventeen".