1981323 has 6 divisors (see below), whose sum is σ = 2861924. Its totient is φ = 1320876.

The previous prime is 1981297. The next prime is 1981337. The reversal of 1981323 is 3231891.

It is a de Polignac number, because none of the positive numbers 2^k-1981323 is a prime.

It is a super-3 number, since 3×1981323³ = 23333887400609835801, which contains 333 as substring.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1981393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 110065 + ... + 110082.

2^1981323 is an apocalyptic number.

1981323 is a deficient number, since it is larger than the sum of its proper divisors (880601).

1981323 is a wasteful number, since it uses less digits than its factorization.

1981323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220153 (or 220150 counting only the distinct ones).

The product of its digits is 1296, while the sum is 27.

The square root of 1981323 is about 1407.5947570235. The cubic root of 1981323 is about 125.5986853623.

It can be divided in two parts, 198132 and 3, that added together give a triangular number (198135 = T₆₂₉).

The spelling of 1981323 in words is "one million, nine hundred eighty-one thousand, three hundred twenty-three".