201666559329 has 45 divisors (see below), whose sum is σ = 309035810281. Its totient is φ = 131057464320.

The previous prime is 201666559327. The next prime is 201666559357. The reversal of 201666559329 is 923955666102.

It is a happy number.

The square root of 201666559329 is 449073.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 90009000225 + 111657559104 = 300015^2 + 334152^2 .

It is not a de Polignac number, because 201666559329 - 2¹ = 201666559327 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (201666559327) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 165707329 + ... + 165708545.

Almost surely, 2^201666559329 is an apocalyptic number.

201666559329 is the 449073-rd square number.

201666559329 is the 224537-th centered octagonal number.

It is an amenable number.

201666559329 is a deficient number, since it is larger than the sum of its proper divisors (107369250952).

201666559329 is an frugal number, since it uses more digits than its factorization.

201666559329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2528 (or 1261 counting only the distinct ones).

The product of its (nonzero) digits is 5248800, while the sum is 54.

The spelling of 201666559329 in words is "two hundred one billion, six hundred sixty-six million, five hundred fifty-nine thousand, three hundred twenty-nine".