1668890880 has 216 divisors, whose sum is σ = 5805078552. Its totient is φ = 442662912.

The previous prime is 1668890863. The next prime is 1668890911. The reversal of 1668890880 is 880988661.

It can be written as a sum of positive squares in 4 ways, for example, as 104530176 + 1564360704 = 10224^2 + 39552^2 .

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3651612 + ... + 3652068.

Almost surely, 2^1668890880 is an apocalyptic number.

1668890880 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1668890880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2902539276).

1668890880 is an abundant number, since it is smaller than the sum of its proper divisors (4136187672).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1668890880 is a wasteful number, since it uses less digits than its factorization.

1668890880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 801 (or 784 counting only the distinct ones).

The product of its (nonzero) digits is 1327104, while the sum is 54.

The square root of 1668890880 is about 40852.0609027256. The cubic root of 1668890880 is about 1186.1582863527.

The spelling of 1668890880 in words is "one billion, six hundred sixty-eight million, eight hundred ninety thousand, eight hundred eighty".