1987986 has 64 divisors (see below), whose sum is σ = 5354496. Its totient is φ = 475200.

The previous prime is 1987981. The next prime is 1987987. The reversal of 1987986 is 6897891.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (1987981) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 5841 + ... + 6171.

It is an arithmetic number, because the mean of its divisors is an integer number (83664).

2^1987986 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1987986, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2677248).

1987986 is an abundant number, since it is smaller than the sum of its proper divisors (3366510).

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

1987986 is a wasteful number, since it uses less digits than its factorization.

1987986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 367.

The product of its digits is 217728, while the sum is 48.

The square root of 1987986 is about 1409.9595738886. The cubic root of 1987986 is about 125.7393199603.

The spelling of 1987986 in words is "one million, nine hundred eighty-seven thousand, nine hundred eighty-six".