1366381 has 4 divisors (see below), whose sum is σ = 1389600. Its totient is φ = 1343164.

The previous prime is 1366367. The next prime is 1366397. The reversal of 1366381 is 1836631.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1836631 = 197 ⋅9323.

It is a cyclic number.

It is not a de Polignac number, because 1366381 - 2⁵ = 1366349 is a prime.

It is a super-2 number, since 2×1366381² = 3733994074322, which contains 22 as substring.

It is a Duffinian number.

1366381 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1366481) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11521 + ... + 11638.

It is an arithmetic number, because the mean of its divisors is an integer number (347400).

2^1366381 is an apocalyptic number.

It is an amenable number.

1366381 is a deficient number, since it is larger than the sum of its proper divisors (23219).

1366381 is an equidigital number, since it uses as much as digits as its factorization.

1366381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23218.

The product of its digits is 2592, while the sum is 28.

The square root of 1366381 is about 1168.9230085853. The cubic root of 1366381 is about 110.9661720904.

The spelling of 1366381 in words is "one million, three hundred sixty-six thousand, three hundred eighty-one".