1287823 has 4 divisors (see below), whose sum is σ = 1292688. Its totient is φ = 1282960.

The previous prime is 1287821. The next prime is 1287829. The reversal of 1287823 is 3287821.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1287823 - 2¹ = 1287821 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1287821) 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, 2011 + ... + 2572.

It is an arithmetic number, because the mean of its divisors is an integer number (323172).

2^1287823 is an apocalyptic number.

1287823 is a deficient number, since it is larger than the sum of its proper divisors (4865).

1287823 is an equidigital number, since it uses as much as digits as its factorization.

1287823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4864.

The product of its digits is 5376, while the sum is 31.

The square root of 1287823 is about 1134.8228936711. The cubic root of 1287823 is about 108.7974523174.

The spelling of 1287823 in words is "one million, two hundred eighty-seven thousand, eight hundred twenty-three".