1666117939 has 2 divisors, whose sum is σ = 1666117940. Its totient is φ = 1666117938.

The previous prime is 1666117927. The next prime is 1666117967. The reversal of 1666117939 is 9397116661.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1666117939 - 2⁷ = 1666117811 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1666117892 and 1666117901.

It is not a weakly prime, because it can be changed into another prime (1666117969) 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, 833058969 + 833058970.

It is an arithmetic number, because the mean of its divisors is an integer number (833058970).

Almost surely, 2^1666117939 is an apocalyptic number.

1666117939 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666117939 is an equidigital number, since it uses as much as digits as its factorization.

1666117939 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 367416, while the sum is 49.

The square root of 1666117939 is about 40818.1079791800. The cubic root of 1666117939 is about 1185.5009694967.

The spelling of 1666117939 in words is "one billion, six hundred sixty-six million, one hundred seventeen thousand, nine hundred thirty-nine".