812381 has 2 divisors, whose sum is σ = 812382. Its totient is φ = 812380.

The previous prime is 812363. The next prime is 812387. The reversal of 812381 is 183218.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 586756 + 225625 = 766^2 + 475^2 .

It is a cyclic number.

It is not a de Polignac number, because 812381 - 2¹⁴ = 795997 is a prime.

It is a super-2 number, since 2×812381² = 1319925778322, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (812387) 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 as a sum of consecutive naturals, namely, 406190 + 406191.

It is an arithmetic number, because the mean of its divisors is an integer number (406191).

2⁸¹²³⁸¹ is an apocalyptic number.

It is an amenable number.

812381 is a deficient number, since it is larger than the sum of its proper divisors (1).

812381 is an equidigital number, since it uses as much as digits as its factorization.

812381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 384, while the sum is 23.

The square root of 812381 is about 901.3218071255. The cubic root of 812381 is about 93.3082231203.

Adding to 812381 its reverse (183218), we get a palindrome (995599).

The spelling of 812381 in words is "eight hundred twelve thousand, three hundred eighty-one".