1318661 has 2 divisors, whose sum is σ = 1318662. Its totient is φ = 1318660.

The previous prime is 1318633. The next prime is 1318663. The reversal of 1318661 is 1668131.

1318661 is nontrivially palindromic in base 2.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 988036 + 330625 = 994^2 + 575^2 .

It is an emirp because it is prime and its reverse (1668131) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1318661 - 2¹⁴ = 1302277 is a prime.

Together with 1318663, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1318661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1318663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 659330 + 659331.

It is an arithmetic number, because the mean of its divisors is an integer number (659331).

2^1318661 is an apocalyptic number.

It is an amenable number.

1318661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1318661 is an equidigital number, since it uses as much as digits as its factorization.

1318661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 26.

The square root of 1318661 is about 1148.3296565011. The cubic root of 1318661 is about 109.6590268029.

The spelling of 1318661 in words is "one million, three hundred eighteen thousand, six hundred sixty-one".