1990489728 has 32 divisors (see below), whose sum is σ = 5287239360. Its totient is φ = 663496448.

The previous prime is 1990489691. The next prime is 1990489747. The reversal of 1990489728 is 8279840991.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2591400 + ... + 2592167.

It is an arithmetic number, because the mean of its divisors is an integer number (165226230).

Almost surely, 2^1990489728 is an apocalyptic number.

It is an amenable number.

1990489728 is an abundant number, since it is smaller than the sum of its proper divisors (3296749632).

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

1990489728 is an equidigital number, since it uses as much as digits as its factorization.

1990489728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5183584 (or 5183572 counting only the distinct ones).

The product of its (nonzero) digits is 2612736, while the sum is 57.

The square root of 1990489728 is about 44614.9047740775. The cubic root of 1990489728 is about 1257.9208441394.

The spelling of 1990489728 in words is "one billion, nine hundred ninety million, four hundred eighty-nine thousand, seven hundred twenty-eight".