1311709661 has 2 divisors, whose sum is σ = 1311709662. Its totient is φ = 1311709660.

The previous prime is 1311709649. The next prime is 1311709697. The reversal of 1311709661 is 1669071131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 923856025 + 387853636 = 30395^2 + 19694^2 .

It is a cyclic number.

It is not a de Polignac number, because 1311709661 - 2¹⁰ = 1311708637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1311709261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655854830 + 655854831.

It is an arithmetic number, because the mean of its divisors is an integer number (655854831).

Almost surely, 2^1311709661 is an apocalyptic number.

It is an amenable number.

1311709661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311709661 is an equidigital number, since it uses as much as digits as its factorization.

1311709661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6804, while the sum is 35.

The square root of 1311709661 is about 36217.5325084413. The cubic root of 1311709661 is about 1094.6599754630.

The spelling of 1311709661 in words is "one billion, three hundred eleven million, seven hundred nine thousand, six hundred sixty-one".