1989631616 has 64 divisors (see below), whose sum is σ = 4572521280. Its totient is φ = 844689408.

The previous prime is 1989631613. The next prime is 1989631639. The reversal of 1989631616 is 6161369891.

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (1989631613) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 85496 + ... + 106248.

It is an arithmetic number, because the mean of its divisors is an integer number (71445645).

Almost surely, 2^1989631616 is an apocalyptic number.

1989631616 is a gapful number since it is divisible by the number (16) 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 1989631616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2286260640).

1989631616 is an abundant number, since it is smaller than the sum of its proper divisors (2582889664).

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

1989631616 is a wasteful number, since it uses less digits than its factorization.

1989631616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20881 (or 20869 counting only the distinct ones).

The product of its digits is 419904, while the sum is 50.

The square root of 1989631616 is about 44605.2868615369. The cubic root of 1989631616 is about 1257.7400524293.

The spelling of 1989631616 in words is "one billion, nine hundred eighty-nine million, six hundred thirty-one thousand, six hundred sixteen".