1669921889 has 2 divisors, whose sum is σ = 1669921890. Its totient is φ = 1669921888.

The previous prime is 1669921873. The next prime is 1669921901. The reversal of 1669921889 is 9881299661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1657141264 + 12780625 = 40708^2 + 3575^2 .

It is a cyclic number.

It is not a de Polignac number, because 1669921889 - 2⁴ = 1669921873 is a prime.

It is a super-2 number, since 2×1669921889² = 5577278230722656642, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1669921189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 834960944 + 834960945.

It is an arithmetic number, because the mean of its divisors is an integer number (834960945).

Almost surely, 2^1669921889 is an apocalyptic number.

It is an amenable number.

1669921889 is a deficient number, since it is larger than the sum of its proper divisors (1).

1669921889 is an equidigital number, since it uses as much as digits as its factorization.

1669921889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3359232, while the sum is 59.

The square root of 1669921889 is about 40864.6777669909. The cubic root of 1669921889 is about 1186.4024980691.

The spelling of 1669921889 in words is "one billion, six hundred sixty-nine million, nine hundred twenty-one thousand, eight hundred eighty-nine".