1989043687 has 2 divisors, whose sum is σ = 1989043688. Its totient is φ = 1989043686.

The previous prime is 1989043643. The next prime is 1989043691. The reversal of 1989043687 is 7863409891.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1989043687 - 2⁷ = 1989043559 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1989043697) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 994521843 + 994521844.

It is an arithmetic number, because the mean of its divisors is an integer number (994521844).

Almost surely, 2^1989043687 is an apocalyptic number.

1989043687 is a deficient number, since it is larger than the sum of its proper divisors (1).

1989043687 is an equidigital number, since it uses as much as digits as its factorization.

1989043687 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2612736, while the sum is 55.

The square root of 1989043687 is about 44598.6960235386. The cubic root of 1989043687 is about 1257.6161543345.

The spelling of 1989043687 in words is "one billion, nine hundred eighty-nine million, forty-three thousand, six hundred eighty-seven".