1668900720 has 160 divisors (see below), whose sum is σ = 5487148800. Its totient is φ = 418424832.

The previous prime is 1668900719. The next prime is 1668900731. The reversal of 1668900720 is 270098661.

It is a super-2 number, since 2×1668900720² = 5570459226433036800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 in 31 ways as a sum of consecutive naturals, for example, 632524 + ... + 635156.

It is an arithmetic number, because the mean of its divisors is an integer number (34294680).

Almost surely, 2^1668900720 is an apocalyptic number.

1668900720 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 1668900720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2743574400).

1668900720 is an abundant number, since it is smaller than the sum of its proper divisors (3818248080).

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

1668900720 is a wasteful number, since it uses less digits than its factorization.

1668900720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2807 (or 2801 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 39.

The square root of 1668900720 is about 40852.1813371085. The cubic root of 1668900720 is about 1186.1606175966.

The spelling of 1668900720 in words is "one billion, six hundred sixty-eight million, nine hundred thousand, seven hundred twenty".