1644479760 has 640 divisors, whose sum is σ = 6849847296. Its totient is φ = 316293120.

The previous prime is 1644479743. The next prime is 1644479821. The reversal of 1644479760 is 679744461.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 22527084 + ... + 22527156.

Almost surely, 2^1644479760 is an apocalyptic number.

1644479760 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 1644479760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3424923648).

1644479760 is an abundant number, since it is smaller than the sum of its proper divisors (5205367536).

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

1644479760 is a wasteful number, since it uses less digits than its factorization.

1644479760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183 (or 177 counting only the distinct ones).

The product of its (nonzero) digits is 1016064, while the sum is 48.

The square root of 1644479760 is about 40552.1856377680. The cubic root of 1644479760 is about 1180.3464844815.

The spelling of 1644479760 in words is "one billion, six hundred forty-four million, four hundred seventy-nine thousand, seven hundred sixty".