201666850020 has 36 divisors (see below), whose sum is σ = 611722778940. Its totient is φ = 53777826624.

The previous prime is 201666850009. The next prime is 201666850051. The reversal of 201666850020 is 20058666102.

It can be written as a sum of positive squares in 2 ways, for example, as 45192807396 + 156474042624 = 212586^2 + 395568^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 560185515 + ... + 560185874.

It is an arithmetic number, because the mean of its divisors is an integer number (16992299415).

Almost surely, 2^201666850020 is an apocalyptic number.

201666850020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

201666850020 is an abundant number, since it is smaller than the sum of its proper divisors (410055928920).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

201666850020 is a wasteful number, since it uses less digits than its factorization.

201666850020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1120371404 (or 1120371399 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The spelling of 201666850020 in words is "two hundred one billion, six hundred sixty-six million, eight hundred fifty thousand, twenty".