1668583521 has 12 divisors (see below), whose sum is σ = 2629283280. Its totient is φ = 1011262680.

The previous prime is 1668583517. The next prime is 1668583537. The reversal of 1668583521 is 1253858661.

1668583521 is a `hidden beast` number, since 1 + 6 + 68 + 583 + 5 + 2 + 1 = 666.

It is not a de Polignac number, because 1668583521 - 2² = 1668583517 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1668583571) 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 in 11 ways as a sum of consecutive naturals, for example, 8427091 + ... + 8427288.

It is an arithmetic number, because the mean of its divisors is an integer number (219106940).

Almost surely, 2^1668583521 is an apocalyptic number.

1668583521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1668583521 is a deficient number, since it is larger than the sum of its proper divisors (960699759).

1668583521 is a wasteful number, since it uses less digits than its factorization.

1668583521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16854396 (or 16854393 counting only the distinct ones).

The product of its digits is 345600, while the sum is 45.

The square root of 1668583521 is about 40848.2988752286. The cubic root of 1668583521 is about 1186.0854637748.

The spelling of 1668583521 in words is "one billion, six hundred sixty-eight million, five hundred eighty-three thousand, five hundred twenty-one".