201666850009 has 2 divisors, whose sum is σ = 201666850010. Its totient is φ = 201666850008.

The previous prime is 201666849931. The next prime is 201666850051. The reversal of 201666850009 is 900058666102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 182951241984 + 18715608025 = 427728^2 + 136805^2 .

It is a cyclic number.

It is not a de Polignac number, because 201666850009 - 2³³ = 193076915417 is a prime.

It is not a weakly prime, because it can be changed into another prime (201666850109) 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, 100833425004 + 100833425005.

It is an arithmetic number, because the mean of its divisors is an integer number (100833425005).

Almost surely, 2^201666850009 is an apocalyptic number.

It is an amenable number.

201666850009 is a deficient number, since it is larger than the sum of its proper divisors (1).

201666850009 is an equidigital number, since it uses as much as digits as its factorization.

201666850009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 155520, while the sum is 43.

The spelling of 201666850009 in words is "two hundred one billion, six hundred sixty-six million, eight hundred fifty thousand, nine".