1989858 has 32 divisors (see below), whose sum is σ = 4346496. Its totient is φ = 603648.

The previous prime is 1989847. The next prime is 1989863. The reversal of 1989858 is 8589891.

It is an Ulam number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7435 + ... + 7697.

It is an arithmetic number, because the mean of its divisors is an integer number (135828).

2^1989858 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1989858, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2173248).

1989858 is an abundant number, since it is smaller than the sum of its proper divisors (2356638).

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

1989858 is a wasteful number, since it uses less digits than its factorization.

1989858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 378.

The product of its digits is 207360, while the sum is 48.

The square root of 1989858 is about 1410.6232665031. The cubic root of 1989858 is about 125.7787753291.

The spelling of 1989858 in words is "one million, nine hundred eighty-nine thousand, eight hundred fifty-eight".