1668809520 has 640 divisors, whose sum is σ = 7147161600. Its totient is φ = 349360128.

The previous prime is 1668809503. The next prime is 1668809531. The reversal of 1668809520 is 259088661.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 10629282 + ... + 10629438.

It is an arithmetic number, because the mean of its divisors is an integer number (11167440).

Almost surely, 2^1668809520 is an apocalyptic number.

1668809520 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 1668809520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3573580800).

1668809520 is an abundant number, since it is smaller than the sum of its proper divisors (5478352080).

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

1668809520 is a wasteful number, since it uses less digits than its factorization.

1668809520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242 (or 230 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 45.

The square root of 1668809520 is about 40851.0651023936. The cubic root of 1668809520 is about 1186.1390105955.

It can be divided in two parts, 166880 and 9520, that added together give a square (176400 = 420²).

The spelling of 1668809520 in words is "one billion, six hundred sixty-eight million, eight hundred nine thousand, five hundred twenty".