1366691 has 4 divisors (see below), whose sum is σ = 1369032. Its totient is φ = 1364352.

The previous prime is 1366667. The next prime is 1366693. The reversal of 1366691 is 1966631.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1966631 = 379 ⋅5189.

It is a cyclic number.

It is not a de Polignac number, because 1366691 - 2⁶ = 1366627 is a prime.

It is a Duffinian number.

It is a plaindrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (1366693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 515 + ... + 1731.

It is an arithmetic number, because the mean of its divisors is an integer number (342258).

2^1366691 is an apocalyptic number.

1366691 is a deficient number, since it is larger than the sum of its proper divisors (2341).

1366691 is a wasteful number, since it uses less digits than its factorization.

1366691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2340.

The product of its digits is 5832, while the sum is 32.

The square root of 1366691 is about 1169.0556017572. The cubic root of 1366691 is about 110.9745633352.

The spelling of 1366691 in words is "one million, three hundred sixty-six thousand, six hundred ninety-one".