1981433 has 4 divisors (see below), whose sum is σ = 1987200. Its totient is φ = 1975668.

The previous prime is 1981429. The next prime is 1981457. The reversal of 1981433 is 3341891.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1981433 - 2² = 1981429 is a prime.

It is a super-3 number, since 3×1981433³ = 23337774000801929211, which contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1981396 and 1981405.

It is not an unprimeable number, because it can be changed into a prime (1981403) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2333 + ... + 3066.

It is an arithmetic number, because the mean of its divisors is an integer number (496800).

2^1981433 is an apocalyptic number.

It is an amenable number.

1981433 is a deficient number, since it is larger than the sum of its proper divisors (5767).

1981433 is an equidigital number, since it uses as much as digits as its factorization.

1981433 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5766.

The product of its digits is 2592, while the sum is 29.

The square root of 1981433 is about 1407.6338302272. The cubic root of 1981433 is about 125.6010096677.

The spelling of 1981433 in words is "one million, nine hundred eighty-one thousand, four hundred thirty-three".