217787020943 has 2 divisors, whose sum is σ = 217787020944. Its totient is φ = 217787020942.

The previous prime is 217787020921. The next prime is 217787020949. The reversal of 217787020943 is 349020787712.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-217787020943 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 217787020891 and 217787020900.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217787020949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108893510471 + 108893510472.

It is an arithmetic number, because the mean of its divisors is an integer number (108893510472).

Almost surely, 2^217787020943 is an apocalyptic number.

217787020943 is a deficient number, since it is larger than the sum of its proper divisors (1).

217787020943 is an equidigital number, since it uses as much as digits as its factorization.

217787020943 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1185408, while the sum is 50.

The spelling of 217787020943 in words is "two hundred seventeen billion, seven hundred eighty-seven million, twenty thousand, nine hundred forty-three".