1261303243 has 4 divisors (see below), whose sum is σ = 1261374480. Its totient is φ = 1261232008.

The previous prime is 1261303237. The next prime is 1261303261. The reversal of 1261303243 is 3423031621.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1261303243 - 2¹³ = 1261295051 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1261303223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13746 + ... + 52072.

It is an arithmetic number, because the mean of its divisors is an integer number (315343620).

Almost surely, 2^1261303243 is an apocalyptic number.

1261303243 is a deficient number, since it is larger than the sum of its proper divisors (71237).

1261303243 is an equidigital number, since it uses as much as digits as its factorization.

1261303243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71236.

The product of its (nonzero) digits is 2592, while the sum is 25.

The square root of 1261303243 is about 35514.8313103132. The cubic root of 1261303243 is about 1080.4545534582.

Adding to 1261303243 its reverse (3423031621), we get a palindrome (4684334864).

The spelling of 1261303243 in words is "one billion, two hundred sixty-one million, three hundred three thousand, two hundred forty-three".