1231009 has 4 divisors (see below), whose sum is σ = 1325716. Its totient is φ = 1136304.

The previous prime is 1231003. The next prime is 1231039. The reversal of 1231009 is 9001321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9001321 = 7 ⋅1285903.

It can be written as a sum of positive squares in 2 ways, for example, as 286225 + 944784 = 535^2 + 972^2 .

It is not a de Polignac number, because 1231009 - 2³ = 1231001 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1230983 and 1231001.

It is not an unprimeable number, because it can be changed into a prime (1231001) 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, 47334 + ... + 47359.

It is an arithmetic number, because the mean of its divisors is an integer number (331429).

2^1231009 is an apocalyptic number.

It is an amenable number.

1231009 is a deficient number, since it is larger than the sum of its proper divisors (94707).

1231009 is an equidigital number, since it uses as much as digits as its factorization.

1231009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94706.

The product of its (nonzero) digits is 54, while the sum is 16.

The square root of 1231009 is about 1109.5084497200. The cubic root of 1231009 is about 107.1734166374.

The spelling of 1231009 in words is "one million, two hundred thirty-one thousand, nine".