1644338729320 has 32 divisors (see below), whose sum is σ = 4228299590400. Its totient is φ = 563773278528.

The previous prime is 1644338729303. The next prime is 1644338729321. The reversal of 1644338729320 is 239278334461.

It is a super-3 number, since 3×1644338729320³ (a number of 38 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1644338729321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2936318880 + ... + 2936319439.

It is an arithmetic number, because the mean of its divisors is an integer number (132134362200).

Almost surely, 2^{1644338729320} is an apocalyptic number.

1644338729320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1644338729320 is an abundant number, since it is smaller than the sum of its proper divisors (2583960861080).

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

1644338729320 is a wasteful number, since it uses less digits than its factorization.

1644338729320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5872638337 (or 5872638333 counting only the distinct ones).

The product of its (nonzero) digits is 5225472, while the sum is 52.

The spelling of 1644338729320 in words is "one trillion, six hundred forty-four billion, three hundred thirty-eight million, seven hundred twenty-nine thousand, three hundred twenty".