1666018091 has 2 divisors, whose sum is σ = 1666018092. Its totient is φ = 1666018090.

The previous prime is 1666018063. The next prime is 1666018103. The reversal of 1666018091 is 1908106661.

It is a strong prime.

It is an emirp because it is prime and its reverse (1908106661) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 1608109991 and 1999018061.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1666018091 is a prime.

It is not a weakly prime, because it can be changed into another prime (1666018051) 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 as a sum of consecutive naturals, namely, 833009045 + 833009046.

It is an arithmetic number, because the mean of its divisors is an integer number (833009046).

Almost surely, 2^1666018091 is an apocalyptic number.

1666018091 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666018091 is an equidigital number, since it uses as much as digits as its factorization.

1666018091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 38.

The square root of 1666018091 is about 40816.8848762372. The cubic root of 1666018091 is about 1185.4772872465.

The spelling of 1666018091 in words is "one billion, six hundred sixty-six million, eighteen thousand, ninety-one".