1668644648 has 64 divisors (see below), whose sum is σ = 3558168000. Its totient is φ = 726865920.

The previous prime is 1668644617. The next prime is 1668644723. The reversal of 1668644648 is 8464468661.

It is a super-2 number, since 2×1668644648² = 5568749922598087808, which contains 22 as substring.

It is a hoax number, since the sum of its digits (53) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 1668644648.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 214328 + ... + 221976.

It is an arithmetic number, because the mean of its divisors is an integer number (55596375).

Almost surely, 2^1668644648 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1668644648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1779084000).

1668644648 is an abundant number, since it is smaller than the sum of its proper divisors (1889523352).

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

1668644648 is a wasteful number, since it uses less digits than its factorization.

1668644648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7770 (or 7766 counting only the distinct ones).

The product of its digits is 5308416, while the sum is 53.

The square root of 1668644648 is about 40849.0470880289. The cubic root of 1668644648 is about 1186.0999473093.

The spelling of 1668644648 in words is "one billion, six hundred sixty-eight million, six hundred forty-four thousand, six hundred forty-eight".