1666201110818 has 4 divisors (see below), whose sum is σ = 2499301666230. Its totient is φ = 833100555408.

The previous prime is 1666201110751. The next prime is 1666201110863. The reversal of 1666201110818 is 8180111026661.

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., 875547589849 + 790653520969 = 935707^2 + 889187^2 .

It is a super-2 number, since 2×1666201110818² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 416550277703 + ... + 416550277706.

Almost surely, 2^{1666201110818} is an apocalyptic number.

1666201110818 is a deficient number, since it is larger than the sum of its proper divisors (833100555412).

1666201110818 is an equidigital number, since it uses as much as digits as its factorization.

1666201110818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 833100555411.

The product of its (nonzero) digits is 27648, while the sum is 41.

The spelling of 1666201110818 in words is "one trillion, six hundred sixty-six billion, two hundred one million, one hundred ten thousand, eight hundred eighteen".