1980640640 has 128 divisors (see below), whose sum is σ = 5186553120. Its totient is φ = 717291520.

The previous prime is 1980640631. The next prime is 1980640657. The reversal of 1980640640 is 460460891.

It is a tau number, because it is divible by the number of its divisors (128).

It is a junction number, because it is equal to n+sod(n) for n = 1980640594 and 1980640603.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2484722 + ... + 2485518.

Almost surely, 2^1980640640 is an apocalyptic number.

1980640640 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 1980640640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2593276560).

1980640640 is an abundant number, since it is smaller than the sum of its proper divisors (3205912480).

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

1980640640 is a wasteful number, since it uses less digits than its factorization.

1980640640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1180 (or 1168 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 1980640640 is about 44504.3889970416. The cubic root of 1980640640 is about 1255.8426513909.

The spelling of 1980640640 in words is "one billion, nine hundred eighty million, six hundred forty thousand, six hundred forty".