1366861 has 2 divisors, whose sum is σ = 1366862. Its totient is φ = 1366860.

The previous prime is 1366843. The next prime is 1366877. The reversal of 1366861 is 1686631.

1366861 is nontrivially palindromic in base 8.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 756900 + 609961 = 870^2 + 781^2 .

It is an emirp because it is prime and its reverse (1686631) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1366861 - 2⁵ = 1366829 is a prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1366801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 683430 + 683431.

It is an arithmetic number, because the mean of its divisors is an integer number (683431).

2^1366861 is an apocalyptic number.

It is an amenable number.

1366861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1366861 is an equidigital number, since it uses as much as digits as its factorization.

1366861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 31.

The square root of 1366861 is about 1169.1283077575. The cubic root of 1366861 is about 110.9791644468.

The spelling of 1366861 in words is "one million, three hundred sixty-six thousand, eight hundred sixty-one".