1990043984 has 20 divisors (see below), whose sum is σ = 3868038516. Its totient is φ = 991840512.

The previous prime is 1990043969. The next prime is 1990043989. The reversal of 1990043984 is 4893400991.

It can be written as a sum of positive squares in 2 ways, for example, as 498539584 + 1491504400 = 22328^2 + 38620^2 .

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1990043989) 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, 193679 + ... + 203694.

Almost surely, 2^1990043984 is an apocalyptic number.

It is an amenable number.

1990043984 is a deficient number, since it is larger than the sum of its proper divisors (1877994532).

1990043984 is a wasteful number, since it uses less digits than its factorization.

1990043984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397694 (or 397688 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 47.

The square root of 1990043984 is about 44609.9090337562. The cubic root of 1990043984 is about 1257.8269388522.

The spelling of 1990043984 in words is "one billion, nine hundred ninety million, forty-three thousand, nine hundred eighty-four".