1989569 has 6 divisors (see below), whose sum is σ = 2080386. Its totient is φ = 1902560.

The previous prime is 1989563. The next prime is 1989571. The reversal of 1989569 is 9659891.

It can be written as a sum of positive squares in only one way, i.e., 1658944 + 330625 = 1288^2 + 575^2 .

It is not a de Polignac number, because 1989569 - 2⁴ = 1989553 is a prime.

It is a super-2 number, since 2×1989569² = 7916769611522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1989563) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1352 + ... + 2409.

It is an arithmetic number, because the mean of its divisors is an integer number (346731).

2^1989569 is an apocalyptic number.

It is an amenable number.

1989569 is a deficient number, since it is larger than the sum of its proper divisors (90817).

1989569 is an equidigital number, since it uses as much as digits as its factorization.

1989569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3807 (or 3784 counting only the distinct ones).

The product of its digits is 174960, while the sum is 47.

The square root of 1989569 is about 1410.5208257945. The cubic root of 1989569 is about 125.7726858115.

The spelling of 1989569 in words is "one million, nine hundred eighty-nine thousand, five hundred sixty-nine".