1644927648 has 288 divisors, whose sum is σ = 5563119744. Its totient is φ = 421521408.

The previous prime is 1644927617. The next prime is 1644927671. The reversal of 1644927648 is 8467294461.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 1644927648.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2262261 + ... + 2262987.

It is an arithmetic number, because the mean of its divisors is an integer number (19316388).

Almost surely, 2^1644927648 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 1644927648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2781559872).

1644927648 is an abundant number, since it is smaller than the sum of its proper divisors (3918192096).

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

1644927648 is a wasteful number, since it uses less digits than its factorization.

1644927648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 804 (or 789 counting only the distinct ones).

The product of its digits is 2322432, while the sum is 51.

The square root of 1644927648 is about 40557.7076275275. The cubic root of 1644927648 is about 1180.4536338773.

The spelling of 1644927648 in words is "one billion, six hundred forty-four million, nine hundred twenty-seven thousand, six hundred forty-eight".