1230781 has 4 divisors (see below), whose sum is σ = 1244700. Its totient is φ = 1216864.

The previous prime is 1230769. The next prime is 1230791. The reversal of 1230781 is 1870321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1870321 = 61 ⋅30661.

It can be written as a sum of positive squares in 2 ways, for example, as 210681 + 1020100 = 459^2 + 1010^2 .

It is a cyclic number.

It is not a de Polignac number, because 1230781 - 2¹⁵ = 1198013 is a prime.

It is a super-2 number, since 2×1230781² = 3029643739922, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

1230781 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1230751) 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, 6826 + ... + 7003.

It is an arithmetic number, because the mean of its divisors is an integer number (311175).

2^1230781 is an apocalyptic number.

It is an amenable number.

1230781 is a deficient number, since it is larger than the sum of its proper divisors (13919).

1230781 is an equidigital number, since it uses as much as digits as its factorization.

1230781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13918.

The product of its (nonzero) digits is 336, while the sum is 22.

The square root of 1230781 is about 1109.4056967584. The cubic root of 1230781 is about 107.1667995594.

The spelling of 1230781 in words is "one million, two hundred thirty thousand, seven hundred eighty-one".