1381231 has 2 divisors, whose sum is σ = 1381232. Its totient is φ = 1381230.

The previous prime is 1381229. The next prime is 1381271. The reversal of 1381231 is 1321831.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1381231 - 2¹ = 1381229 is a prime.

It is a super-3 number, since 3×1381231³ = 7905333673979848173, which contains 333 as substring. Note that it is a super-d number also for d = 2.

Together with 1381229, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 1381199 and 1381208.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1381271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 690615 + 690616.

It is an arithmetic number, because the mean of its divisors is an integer number (690616).

2^1381231 is an apocalyptic number.

1381231 is a deficient number, since it is larger than the sum of its proper divisors (1).

1381231 is an equidigital number, since it uses as much as digits as its factorization.

1381231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 144, while the sum is 19.

The square root of 1381231 is about 1175.2578440496. The cubic root of 1381231 is about 111.3667225881.

It can be divided in two parts, 138 and 1231, that added together give a square (1369 = 37²).

The spelling of 1381231 in words is "one million, three hundred eighty-one thousand, two hundred thirty-one".