1666870187 has 2 divisors, whose sum is σ = 1666870188. Its totient is φ = 1666870186.

The previous prime is 1666870109. The next prime is 1666870199. The reversal of 1666870187 is 7810786661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1666870187 - 2²⁸ = 1398434731 is a prime.

It is not a weakly prime, because it can be changed into another prime (1666876187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833435093 + 833435094.

It is an arithmetic number, because the mean of its divisors is an integer number (833435094).

Almost surely, 2^1666870187 is an apocalyptic number.

1666870187 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666870187 is an equidigital number, since it uses as much as digits as its factorization.

1666870187 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 677376, while the sum is 50.

The square root of 1666870187 is about 40827.3215751413. The cubic root of 1666870187 is about 1185.6793595398.

The spelling of 1666870187 in words is "one billion, six hundred sixty-six million, eight hundred seventy thousand, one hundred eighty-seven".