1665646139 has 2 divisors, whose sum is σ = 1665646140. Its totient is φ = 1665646138.

The previous prime is 1665646133. The next prime is 1665646159. The reversal of 1665646139 is 9316465661.

It is a weak prime.

It is an emirp because it is prime and its reverse (9316465661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1665646139 - 2⁴ = 1665646123 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1665646093 and 1665646102.

It is not a weakly prime, because it can be changed into another prime (1665646133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832823069 + 832823070.

It is an arithmetic number, because the mean of its divisors is an integer number (832823070).

Almost surely, 2^1665646139 is an apocalyptic number.

1665646139 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665646139 is an equidigital number, since it uses as much as digits as its factorization.

1665646139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 699840, while the sum is 47.

The square root of 1665646139 is about 40812.3282722268. The cubic root of 1665646139 is about 1185.3890582193.

The spelling of 1665646139 in words is "one billion, six hundred sixty-five million, six hundred forty-six thousand, one hundred thirty-nine".