1312304216261 has 4 divisors (see below), whose sum is σ = 1312350861024. Its totient is φ = 1312257571500.

The previous prime is 1312304216243. The next prime is 1312304216281. The reversal of 1312304216261 is 1626124032131.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1312304216261 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1312304216281) 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, 23280155 + ... + 23336456.

It is an arithmetic number, because the mean of its divisors is an integer number (328087715256).

Almost surely, 2^{1312304216261} is an apocalyptic number.

It is an amenable number.

1312304216261 is a deficient number, since it is larger than the sum of its proper divisors (46644763).

1312304216261 is an equidigital number, since it uses as much as digits as its factorization.

1312304216261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46644762.

The product of its (nonzero) digits is 10368, while the sum is 32.

Adding to 1312304216261 its reverse (1626124032131), we get a palindrome (2938428248392).

The spelling of 1312304216261 in words is "one trillion, three hundred twelve billion, three hundred four million, two hundred sixteen thousand, two hundred sixty-one".