1989743 has 8 divisors (see below), whose sum is σ = 2320800. Its totient is φ = 1705200.

The previous prime is 1989721. The next prime is 1989769. The reversal of 1989743 is 3479891.

It is a happy number.

It is not a de Polignac number, because 1989743 - 2⁶ = 1989679 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1989743.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1989643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2558 + ... + 3243.

It is an arithmetic number, because the mean of its divisors is an integer number (290100).

2^1989743 is an apocalyptic number.

1989743 is a deficient number, since it is larger than the sum of its proper divisors (331057).

1989743 is an frugal number, since it uses more digits than its factorization.

1989743 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5822 (or 5808 counting only the distinct ones).

The product of its digits is 54432, while the sum is 41.

The square root of 1989743 is about 1410.5825037905. The cubic root of 1989743 is about 125.7763522353.

The spelling of 1989743 in words is "one million, nine hundred eighty-nine thousand, seven hundred forty-three".