1311461961 has 4 divisors (see below), whose sum is σ = 1748615952. Its totient is φ = 874307972.

The previous prime is 1311461927. The next prime is 1311461989. The reversal of 1311461961 is 1691641131.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1691641131 = 3 ⋅563880377.

It is a cyclic number.

It is not a de Polignac number, because 1311461961 - 2⁶ = 1311461897 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1311461911) 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, 218576991 + ... + 218576996.

It is an arithmetic number, because the mean of its divisors is an integer number (437153988).

Almost surely, 2^1311461961 is an apocalyptic number.

It is an amenable number.

1311461961 is a deficient number, since it is larger than the sum of its proper divisors (437153991).

1311461961 is an equidigital number, since it uses as much as digits as its factorization.

1311461961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 437153990.

The product of its digits is 3888, while the sum is 33.

The square root of 1311461961 is about 36214.1127324694. The cubic root of 1311461961 is about 1094.5910668334.

The spelling of 1311461961 in words is "one billion, three hundred eleven million, four hundred sixty-one thousand, nine hundred sixty-one".