1989900 has 144 divisors (see below), whose sum is σ = 7082880. Its totient is φ = 475200.

The previous prime is 1989899. The next prime is 1989919. The reversal of 1989900 is 99891.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 29667 + ... + 29733.

2^1989900 is an apocalyptic number.

1989900 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1989900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3541440).

1989900 is an abundant number, since it is smaller than the sum of its proper divisors (5092980).

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

1989900 is a wasteful number, since it uses less digits than its factorization.

1989900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101 (or 88 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 36.

The square root of 1989900 is about 1410.6381534610. The cubic root of 1989900 is about 125.7796602618.

The spelling of 1989900 in words is "one million, nine hundred eighty-nine thousand, nine hundred".