1000381 has 2 divisors, whose sum is σ = 1000382. Its totient is φ = 1000380.

The previous prime is 1000367. The next prime is 1000393. The reversal of 1000381 is 1830001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 783225 + 217156 = 885^2 + 466^2 .

It is a cyclic number.

It is not a de Polignac number, because 1000381 - 2⁷ = 1000253 is a prime.

It is a super-2 number, since 2×1000381² = 2001524290322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1000081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500190 + 500191.

It is an arithmetic number, because the mean of its divisors is an integer number (500191).

2^1000381 is an apocalyptic number.

It is an amenable number.

1000381 is a deficient number, since it is larger than the sum of its proper divisors (1).

1000381 is an equidigital number, since it uses as much as digits as its factorization.

1000381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1000381 is about 1000.1904818583. The cubic root of 1000381 is about 100.0126983874.

Adding to 1000381 its product of nonzero digits (24), we get a triangular number (1000405 = T₁₄₁₄).

Adding to 1000381 its reverse (1830001), we get a palindrome (2830382).

The spelling of 1000381 in words is "one million, three hundred eighty-one", and thus it is an aban number.