201666386 has 4 divisors (see below), whose sum is σ = 302499582. Its totient is φ = 100833192.

The previous prime is 201666383. The next prime is 201666403. The reversal of 201666386 is 683666102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 164224225 + 37442161 = 12815^2 + 6119^2 .

It is not an unprimeable number, because it can be changed into a prime (201666383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50416595 + ... + 50416598.

Almost surely, 2^201666386 is an apocalyptic number.

201666386 is a deficient number, since it is larger than the sum of its proper divisors (100833196).

201666386 is a wasteful number, since it uses less digits than its factorization.

201666386 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100833195.

The product of its (nonzero) digits is 62208, while the sum is 38.

The square root of 201666386 is about 14200.9290541147. The cubic root of 201666386 is about 586.4232382948.

The spelling of 201666386 in words is "two hundred one million, six hundred sixty-six thousand, three hundred eighty-six".