1989564 has 24 divisors (see below), whose sum is σ = 4768848. Its totient is φ = 645120.

The previous prime is 1989563. The next prime is 1989571. The reversal of 1989564 is 4659891.

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 7 ways as a sum of consecutive naturals, for example, 1797 + ... + 2684.

It is an arithmetic number, because the mean of its divisors is an integer number (198702).

2^1989564 is an apocalyptic number.

It is an amenable number.

1989564 is an abundant number, since it is smaller than the sum of its proper divisors (2779284).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1989564 is a wasteful number, since it uses less digits than its factorization.

1989564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4525 (or 4523 counting only the distinct ones).

The product of its digits is 77760, while the sum is 42.

The square root of 1989564 is about 1410.5190533984. The cubic root of 1989564 is about 125.7725804513.

The spelling of 1989564 in words is "one million, nine hundred eighty-nine thousand, five hundred sixty-four".