8216081057381 has 2 divisors, whose sum is σ = 8216081057382. Its totient is φ = 8216081057380.

The previous prime is 8216081057357. The next prime is 8216081057383. The reversal of 8216081057381 is 1837501806128.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5516415177025 + 2699665880356 = 2348705^2 + 1643066^2 .

It is a cyclic number.

It is not a de Polignac number, because 8216081057381 - 2¹⁰ = 8216081056357 is a prime.

It is a super-2 number, since 2×8216081057381² (a number of 27 digits) contains 22 as substring.

Together with 8216081057383, 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 (8216081057383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4108040528690 + 4108040528691.

It is an arithmetic number, because the mean of its divisors is an integer number (4108040528691).

Almost surely, 2^{8216081057381} is an apocalyptic number.

It is an amenable number.

8216081057381 is a deficient number, since it is larger than the sum of its proper divisors (1).

8216081057381 is an equidigital number, since it uses as much as digits as its factorization.

8216081057381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 645120, while the sum is 50.

The spelling of 8216081057381 in words is "eight trillion, two hundred sixteen billion, eighty-one million, fifty-seven thousand, three hundred eighty-one".