231220203218117 has 2 divisors, whose sum is σ = 231220203218118. Its totient is φ = 231220203218116.

The previous prime is 231220203218107. The next prime is 231220203218141. The reversal of 231220203218117 is 711812302022132.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 158017822224196 + 73202380993921 = 12570514^2 + 8555839^2 .

It is a cyclic number.

It is not a de Polignac number, because 231220203218117 - 2¹⁶ = 231220203152581 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231220203218107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115610101609058 + 115610101609059.

It is an arithmetic number, because the mean of its divisors is an integer number (115610101609059).

Almost surely, 2^{231220203218117} is an apocalyptic number.

It is an amenable number.

231220203218117 is a deficient number, since it is larger than the sum of its proper divisors (1).

231220203218117 is an equidigital number, since it uses as much as digits as its factorization.

231220203218117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16128, while the sum is 35.

The spelling of 231220203218117 in words is "two hundred thirty-one trillion, two hundred twenty billion, two hundred three million, two hundred eighteen thousand, one hundred seventeen".