1281723 has 4 divisors (see below), whose sum is σ = 1708968. Its totient is φ = 854480.

The previous prime is 1281703. The next prime is 1281727. The reversal of 1281723 is 3271821.

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 1281723 - 2⁵ = 1281691 is a prime.

It is a D-number.

It is a junction number, because it is equal to n+sod(n) for n = 1281693 and 1281702.

It is not an unprimeable number, because it can be changed into a prime (1281727) 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 3 ways as a sum of consecutive naturals, for example, 213618 + ... + 213623.

It is an arithmetic number, because the mean of its divisors is an integer number (427242).

2^1281723 is an apocalyptic number.

1281723 is a deficient number, since it is larger than the sum of its proper divisors (427245).

1281723 is an equidigital number, since it uses as much as digits as its factorization.

1281723 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427244.

The product of its digits is 672, while the sum is 24.

The square root of 1281723 is about 1132.1320594348. The cubic root of 1281723 is about 108.6254009616.

The spelling of 1281723 in words is "one million, two hundred eighty-one thousand, seven hundred twenty-three".