1209723 has 4 divisors (see below), whose sum is σ = 1612968. Its totient is φ = 806480.

The previous prime is 1209709. The next prime is 1209739. The reversal of 1209723 is 3279021.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3279021 = 3 ⋅1093007.

It is a cyclic number.

It is not a de Polignac number, because 1209723 - 2⁴ = 1209707 is a prime.

It is a D-number.

It is a junction number, because it is equal to n+sod(n) for n = 1209693 and 1209702.

It is not an unprimeable number, because it can be changed into a prime (1209763) 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, 201618 + ... + 201623.

It is an arithmetic number, because the mean of its divisors is an integer number (403242).

2^1209723 is an apocalyptic number.

1209723 is a deficient number, since it is larger than the sum of its proper divisors (403245).

1209723 is an equidigital number, since it uses as much as digits as its factorization.

1209723 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 403244.

The product of its (nonzero) digits is 756, while the sum is 24.

The square root of 1209723 is about 1099.8740837023. The cubic root of 1209723 is about 106.5520916010.

The spelling of 1209723 in words is "one million, two hundred nine thousand, seven hundred twenty-three".