1669939987 has 2 divisors, whose sum is σ = 1669939988. Its totient is φ = 1669939986.

The previous prime is 1669939979. The next prime is 1669940099. The reversal of 1669939987 is 7899399661.

It is a weak prime.

It is an emirp because it is prime and its reverse (7899399661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1669939987 - 2³ = 1669939979 is a prime.

It is not a weakly prime, because it can be changed into another prime (1669939967) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 834969993 + 834969994.

It is an arithmetic number, because the mean of its divisors is an integer number (834969994).

Almost surely, 2^1669939987 is an apocalyptic number.

1669939987 is a deficient number, since it is larger than the sum of its proper divisors (1).

1669939987 is an equidigital number, since it uses as much as digits as its factorization.

1669939987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 39680928, while the sum is 67.

The square root of 1669939987 is about 40864.8992045741. The cubic root of 1669939987 is about 1186.4067839851.

The spelling of 1669939987 in words is "one billion, six hundred sixty-nine million, nine hundred thirty-nine thousand, nine hundred eighty-seven".