1668080640 has 176 divisors, whose sum is σ = 5382463680. Its totient is φ = 440893440.

The previous prime is 1668080633. The next prime is 1668080641. The reversal of 1668080640 is 460808661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1668080641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2011746 + ... + 2012574.

It is an arithmetic number, because the mean of its divisors is an integer number (30582180).

Almost surely, 2^1668080640 is an apocalyptic number.

1668080640 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 1668080640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2691231840).

1668080640 is an abundant number, since it is smaller than the sum of its proper divisors (3714383040).

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

1668080640 is a wasteful number, since it uses less digits than its factorization.

1668080640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 988 (or 970 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 39.

The square root of 1668080640 is about 40842.1429408399. The cubic root of 1668080640 is about 1185.9662968752.

The spelling of 1668080640 in words is "one billion, six hundred sixty-eight million, eighty thousand, six hundred forty".