1311436781 has 2 divisors, whose sum is σ = 1311436782. Its totient is φ = 1311436780.

The previous prime is 1311436733. The next prime is 1311436787. The reversal of 1311436781 is 1876341131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1305015625 + 6421156 = 36125^2 + 2534^2 .

It is a cyclic number.

It is not a de Polignac number, because 1311436781 - 2¹⁰ = 1311435757 is a prime.

It is a super-2 number, since 2×1311436781² = 3439732861119283922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1311436787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655718390 + 655718391.

It is an arithmetic number, because the mean of its divisors is an integer number (655718391).

Almost surely, 2^1311436781 is an apocalyptic number.

It is an amenable number.

1311436781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311436781 is an equidigital number, since it uses as much as digits as its factorization.

1311436781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 35.

The square root of 1311436781 is about 36213.7650762800. The cubic root of 1311436781 is about 1094.5840614251.

The spelling of 1311436781 in words is "one billion, three hundred eleven million, four hundred thirty-six thousand, seven hundred eighty-one".