1668439441 has 2 divisors, whose sum is σ = 1668439442. Its totient is φ = 1668439440.

The previous prime is 1668439391. The next prime is 1668439453. The reversal of 1668439441 is 1449348661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1428840000 + 239599441 = 37800^2 + 15479^2 .

It is a cyclic number.

It is not a de Polignac number, because 1668439441 - 2²⁵ = 1634885009 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1668439391 and 1668439400.

It is not a weakly prime, because it can be changed into another prime (1668439741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 834219720 + 834219721.

It is an arithmetic number, because the mean of its divisors is an integer number (834219721).

Almost surely, 2^1668439441 is an apocalyptic number.

It is an amenable number.

1668439441 is a deficient number, since it is larger than the sum of its proper divisors (1).

1668439441 is an equidigital number, since it uses as much as digits as its factorization.

1668439441 is an evil number, because the sum of its binary digits is even.

The product of its digits is 497664, while the sum is 46.

The square root of 1668439441 is about 40846.5352386221. The cubic root of 1668439441 is about 1186.0513238171.

The spelling of 1668439441 in words is "one billion, six hundred sixty-eight million, four hundred thirty-nine thousand, four hundred forty-one".