1666870181 has 8 divisors (see below), whose sum is σ = 1702923264. Its totient is φ = 1630841680.

The previous prime is 1666870109. The next prime is 1666870187. The reversal of 1666870181 is 1810786661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1666870181 is a prime.

It is a super-2 number, since 2×1666870181² = 5556912400613945522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666870187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 217271 + ... + 224811.

It is an arithmetic number, because the mean of its divisors is an integer number (212865408).

Almost surely, 2^1666870181 is an apocalyptic number.

It is an amenable number.

1666870181 is a deficient number, since it is larger than the sum of its proper divisors (36053083).

1666870181 is an equidigital number, since it uses as much as digits as its factorization.

1666870181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12291.

The product of its (nonzero) digits is 96768, while the sum is 44.

The square root of 1666870181 is about 40827.3215016611. The cubic root of 1666870181 is about 1185.6793581172.

The spelling of 1666870181 in words is "one billion, six hundred sixty-six million, eight hundred seventy thousand, one hundred eighty-one".