201857380666 has 4 divisors (see below), whose sum is σ = 302786071002. Its totient is φ = 100928690332.

The previous prime is 201857380663. The next prime is 201857380667. The reversal of 201857380666 is 666083758102.

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., 199473890625 + 2383490041 = 446625^2 + 48821^2 .

It is not an unprimeable number, because it can be changed into a prime (201857380663) 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, 50464345165 + ... + 50464345168.

Almost surely, 2^201857380666 is an apocalyptic number.

201857380666 is a deficient number, since it is larger than the sum of its proper divisors (100928690336).

201857380666 is a wasteful number, since it uses less digits than its factorization.

201857380666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100928690335.

The product of its (nonzero) digits is 2903040, while the sum is 52.

The spelling of 201857380666 in words is "two hundred one billion, eight hundred fifty-seven million, three hundred eighty thousand, six hundred sixty-six".