1644494568 has 16 divisors (see below), whose sum is σ = 4111236480. Its totient is φ = 548164848.

The previous prime is 1644494557. The next prime is 1644494617. The reversal of 1644494568 is 8654944461.

It is a self number, because there is not a number n which added to its sum of digits gives 1644494568.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34260280 + ... + 34260327.

It is an arithmetic number, because the mean of its divisors is an integer number (256952280).

Almost surely, 2^1644494568 is an apocalyptic number.

It is an amenable number.

1644494568 is an abundant number, since it is smaller than the sum of its proper divisors (2466741912).

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

1644494568 is a wasteful number, since it uses less digits than its factorization.

1644494568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68520616 (or 68520612 counting only the distinct ones).

The product of its digits is 3317760, while the sum is 51.

The square root of 1644494568 is about 40552.3682169118. The cubic root of 1644494568 is about 1180.3500273483.

The spelling of 1644494568 in words is "one billion, six hundred forty-four million, four hundred ninety-four thousand, five hundred sixty-eight".