8021381 has 2 divisors, whose sum is σ = 8021382. Its totient is φ = 8021380.

The previous prime is 8021359. The next prime is 8021383. The reversal of 8021381 is 1831208.

8021381 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6421156 + 1600225 = 2534^2 + 1265^2 .

It is a cyclic number.

It is not a de Polignac number, because 8021381 - 2¹⁰ = 8020357 is a prime.

It is a super-2 number, since 2×8021381² = 128685106294322, which contains 22 as substring.

Together with 8021383, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8021383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4010690 + 4010691.

It is an arithmetic number, because the mean of its divisors is an integer number (4010691).

Almost surely, 2^8021381 is an apocalyptic number.

It is an amenable number.

8021381 is a deficient number, since it is larger than the sum of its proper divisors (1).

8021381 is an equidigital number, since it uses as much as digits as its factorization.

8021381 is an evil number, because the sum of its binary digits is even.

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

The square root of 8021381 is about 2832.2042652323. The cubic root of 8021381 is about 200.1780165036.

Adding to 8021381 its reverse (1831208), we get a palindrome (9852589).

The spelling of 8021381 in words is "eight million, twenty-one thousand, three hundred eighty-one".