1781423 has 4 divisors (see below), whose sum is σ = 2035920. Its totient is φ = 1526928.

The previous prime is 1781407. The next prime is 1781449. The reversal of 1781423 is 3241871.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3241871 = 433 ⋅7487.

It is a cyclic number.

It is not a de Polignac number, because 1781423 - 2⁴ = 1781407 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1781392 and 1781401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1781453) 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, 127238 + ... + 127251.

It is an arithmetic number, because the mean of its divisors is an integer number (508980).

2^1781423 is an apocalyptic number.

1781423 is a deficient number, since it is larger than the sum of its proper divisors (254497).

1781423 is an equidigital number, since it uses as much as digits as its factorization.

1781423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 254496.

The product of its digits is 1344, while the sum is 26.

The square root of 1781423 is about 1334.6995916685. The cubic root of 1781423 is about 121.2241139340.

The spelling of 1781423 in words is "one million, seven hundred eighty-one thousand, four hundred twenty-three".