217550055631 has 2 divisors, whose sum is σ = 217550055632. Its totient is φ = 217550055630.

The previous prime is 217550055607. The next prime is 217550055713. The reversal of 217550055631 is 136550055712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 217550055631 - 2¹¹ = 217550053583 is a prime.

It is a super-2 number, since 2×217550055631² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217550055031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108775027815 + 108775027816.

It is an arithmetic number, because the mean of its divisors is an integer number (108775027816).

Almost surely, 2^217550055631 is an apocalyptic number.

217550055631 is a deficient number, since it is larger than the sum of its proper divisors (1).

217550055631 is an equidigital number, since it uses as much as digits as its factorization.

217550055631 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 157500, while the sum is 40.

The spelling of 217550055631 in words is "two hundred seventeen billion, five hundred fifty million, fifty-five thousand, six hundred thirty-one".