1989634688 has 32 divisors (see below), whose sum is σ = 4136067360. Its totient is φ = 951563008.

The previous prime is 1989634687. The next prime is 1989634693. The reversal of 1989634688 is 8864369891.

It is a tau number, because it is divible by the number of its divisors (32).

It is a self number, because there is not a number n which added to its sum of digits gives 1989634688.

It is not an unprimeable number, because it can be changed into a prime (1989634687) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 334970 + ... + 340857.

It is an arithmetic number, because the mean of its divisors is an integer number (129252105).

Almost surely, 2^1989634688 is an apocalyptic number.

It is an amenable number.

1989634688 is an abundant number, since it is smaller than the sum of its proper divisors (2146432672).

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

1989634688 is an equidigital number, since it uses as much as digits as its factorization.

1989634688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 675864 (or 675852 counting only the distinct ones).

The product of its digits is 17915904, while the sum is 62.

The square root of 1989634688 is about 44605.3212969036. The cubic root of 1989634688 is about 1257.7406997477.

The spelling of 1989634688 in words is "one billion, nine hundred eighty-nine million, six hundred thirty-four thousand, six hundred eighty-eight".