1988971489 has 2 divisors, whose sum is σ = 1988971490. Its totient is φ = 1988971488.

The previous prime is 1988971469. The next prime is 1988971513. The reversal of 1988971489 is 9841798891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1053651600 + 935319889 = 32460^2 + 30583^2 .

It is a cyclic number.

It is not a de Polignac number, because 1988971489 - 2¹¹ = 1988969441 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1988971489.

It is not a weakly prime, because it can be changed into another prime (1988971469) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 994485744 + 994485745.

It is an arithmetic number, because the mean of its divisors is an integer number (994485745).

Almost surely, 2^1988971489 is an apocalyptic number.

It is an amenable number.

1988971489 is a deficient number, since it is larger than the sum of its proper divisors (1).

1988971489 is an equidigital number, since it uses as much as digits as its factorization.

1988971489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10450944, while the sum is 64.

The square root of 1988971489 is about 44597.8865979095. The cubic root of 1988971489 is about 1257.6009378982.

It can be divided in two parts, 19889 and 71489, that added together give a triangular number (91378 = T₄₂₇).

The spelling of 1988971489 in words is "one billion, nine hundred eighty-eight million, nine hundred seventy-one thousand, four hundred eighty-nine".