1669921871 has 2 divisors, whose sum is σ = 1669921872. Its totient is φ = 1669921870.

The previous prime is 1669921867. The next prime is 1669921873. The reversal of 1669921871 is 1781299661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1669921871 - 2² = 1669921867 is a prime.

It is a Sophie Germain prime.

Together with 1669921873, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1669921873) 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, 834960935 + 834960936.

It is an arithmetic number, because the mean of its divisors is an integer number (834960936).

Almost surely, 2^1669921871 is an apocalyptic number.

1669921871 is a deficient number, since it is larger than the sum of its proper divisors (1).

1669921871 is an equidigital number, since it uses as much as digits as its factorization.

1669921871 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 326592, while the sum is 50.

The square root of 1669921871 is about 40864.6775467518. The cubic root of 1669921871 is about 1186.4024938064.

The spelling of 1669921871 in words is "one billion, six hundred sixty-nine million, nine hundred twenty-one thousand, eight hundred seventy-one".