It is an unprimeable number.
21987650 is an apocalyptic number.
1987650 is a gapful number since it is divisible by the number (10) formed by its first and last digit.
It is a practical number, because each smaller number is the sum of distinct divisors of 1987650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3056352).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
1987650 is a wasteful number, since it uses less digits than its factorization.
1987650 is an odious number, because the sum of its binary digits is odd.
The square root of 1987650 is about 1409.8404165011. The cubic root of 1987650 is about 125.7322356060.
The spelling of 1987650 in words is "one million, nine hundred eighty-seven thousand, six hundred fifty".