1981986 has 8 divisors (see below), whose sum is σ = 3963984. Its totient is φ = 660660.

The previous prime is 1981963. The next prime is 1981997. The reversal of 1981986 is 6891891.

It is a sphenic number, since it is the product of 3 distinct primes.

1981986 is an admirable number.

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 3 ways as a sum of consecutive naturals, for example, 165160 + ... + 165171.

It is an arithmetic number, because the mean of its divisors is an integer number (495498).

2^1981986 is an apocalyptic number.

1981986 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

1981986 is a wasteful number, since it uses less digits than its factorization.

1981986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330336.

The product of its digits is 31104, while the sum is 42.

The square root of 1981986 is about 1407.8302454486. The cubic root of 1981986 is about 125.6126932822.

The spelling of 1981986 in words is "one million, nine hundred eighty-one thousand, nine hundred eighty-six".