1981968 has 40 divisors (see below), whose sum is σ = 5172288. Its totient is φ = 653952.

The previous prime is 1981963. The next prime is 1981997. The reversal of 1981968 is 8691891.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (1981963) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7405 + ... + 7667.

2^1981968 is an apocalyptic number.

It is an amenable number.

1981968 is an abundant number, since it is smaller than the sum of its proper divisors (3190320).

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

1981968 is a wasteful number, since it uses less digits than its factorization.

1981968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431 (or 425 counting only the distinct ones).

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

The square root of 1981968 is about 1407.8238526179. The cubic root of 1981968 is about 125.6123130179.

The spelling of 1981968 in words is "one million, nine hundred eighty-one thousand, nine hundred sixty-eight".