1988631680 has 128 divisors (see below), whose sum is σ = 5544720000. Its totient is φ = 681741312.

The previous prime is 1988631653. The next prime is 1988631691. The reversal of 1988631680 is 861368891.

It is a happy number.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 214991 + ... + 224049.

It is an arithmetic number, because the mean of its divisors is an integer number (43318125).

Almost surely, 2^1988631680 is an apocalyptic number.

1988631680 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 1988631680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2772360000).

1988631680 is an abundant number, since it is smaller than the sum of its proper divisors (3556088320).

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

1988631680 is an frugal number, since it uses more digits than its factorization.

1988631680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9099 (or 9073 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 50.

The square root of 1988631680 is about 44594.0767367147. The cubic root of 1988631680 is about 1257.5293148746.

The spelling of 1988631680 in words is "one billion, nine hundred eighty-eight million, six hundred thirty-one thousand, six hundred eighty".