1318397661 has 32 divisors (see below), whose sum is σ = 2234777600. Its totient is φ = 752502960.

The previous prime is 1318397621. The next prime is 1318397671. The reversal of 1318397661 is 1667938131.

It is not a de Polignac number, because 1318397661 - 2¹¹ = 1318395613 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1318397621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 183780 + ... + 190818.

It is an arithmetic number, because the mean of its divisors is an integer number (69836800).

Almost surely, 2^1318397661 is an apocalyptic number.

It is an amenable number.

1318397661 is a deficient number, since it is larger than the sum of its proper divisors (916379939).

1318397661 is an equidigital number, since it uses as much as digits as its factorization.

1318397661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8046 (or 8040 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 1318397661 is about 36309.7460883438. The cubic root of 1318397661 is about 1096.5172661454.

The spelling of 1318397661 in words is "one billion, three hundred eighteen million, three hundred ninety-seven thousand, six hundred sixty-one".