1331381 has 2 divisors, whose sum is σ = 1331382. Its totient is φ = 1331380.

The previous prime is 1331377. The next prime is 1331383. The reversal of 1331381 is 1831331.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 707281 + 624100 = 841^2 + 790^2 .

It is an emirp because it is prime and its reverse (1831331) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1331381 - 2² = 1331377 is a prime.

It is a super-2 number, since 2×1331381² = 3545150734322, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 1331383, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a plaindrome in base 13.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1331383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 665690 + 665691.

It is an arithmetic number, because the mean of its divisors is an integer number (665691).

2^1331381 is an apocalyptic number.

It is an amenable number.

1331381 is a deficient number, since it is larger than the sum of its proper divisors (1).

1331381 is an equidigital number, since it uses as much as digits as its factorization.

1331381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 216, while the sum is 20.

The square root of 1331381 is about 1153.8548435570. The cubic root of 1331381 is about 110.0104948664.

The spelling of 1331381 in words is "one million, three hundred thirty-one thousand, three hundred eighty-one".