1989644143 has 2 divisors, whose sum is σ = 1989644144. Its totient is φ = 1989644142.

The previous prime is 1989644089. The next prime is 1989644161. The reversal of 1989644143 is 3414469891.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1989644143 - 2⁹ = 1989643631 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1989644743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 994822071 + 994822072.

It is an arithmetic number, because the mean of its divisors is an integer number (994822072).

Almost surely, 2^1989644143 is an apocalyptic number.

1989644143 is a deficient number, since it is larger than the sum of its proper divisors (1).

1989644143 is an equidigital number, since it uses as much as digits as its factorization.

1989644143 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 746496, while the sum is 49.

The square root of 1989644143 is about 44605.4272818903. The cubic root of 1989644143 is about 1257.7426920597.

The spelling of 1989644143 in words is "one billion, nine hundred eighty-nine million, six hundred forty-four thousand, one hundred forty-three".