1646681568 has 96 divisors (see below), whose sum is σ = 4948263936. Its totient is φ = 469698048.

The previous prime is 1646681551. The next prime is 1646681581. The reversal of 1646681568 is 8651866461.

It is a tau number, because it is divible by the number of its divisors (96).

Its product of digits (1658880) is a multiple of the sum of its prime factors (4096).

It is a self number, because there is not a number n which added to its sum of digits gives 1646681568.

It is a congruent number.

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, 490905 + ... + 494247.

It is an arithmetic number, because the mean of its divisors is an integer number (51544416).

Almost surely, 2^1646681568 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 1646681568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2474131968).

1646681568 is an abundant number, since it is smaller than the sum of its proper divisors (3301582368).

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

1646681568 is a wasteful number, since it uses less digits than its factorization.

1646681568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4096 (or 4088 counting only the distinct ones).

The product of its digits is 1658880, while the sum is 51.

The square root of 1646681568 is about 40579.3243906303. The cubic root of 1646681568 is about 1180.8730415448.

The spelling of 1646681568 in words is "one billion, six hundred forty-six million, six hundred eighty-one thousand, five hundred sixty-eight".