8138256481 has 2 divisors, whose sum is σ = 8138256482. Its totient is φ = 8138256480.

The previous prime is 8138256437. The next prime is 8138256487. The reversal of 8138256481 is 1846528318.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4972506256 + 3165750225 = 70516^2 + 56265^2 .

It is a cyclic number.

It is not a de Polignac number, because 8138256481 - 2²¹ = 8136159329 is a prime.

It is a super-2 number, since 2×8138256481² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (8138256487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4069128240 + 4069128241.

It is an arithmetic number, because the mean of its divisors is an integer number (4069128241).

Almost surely, 2^8138256481 is an apocalyptic number.

It is an amenable number.

8138256481 is a deficient number, since it is larger than the sum of its proper divisors (1).

8138256481 is an equidigital number, since it uses as much as digits as its factorization.

8138256481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 368640, while the sum is 46.

The square root of 8138256481 is about 90212.2856433646. The cubic root of 8138256481 is about 2011.4556323817.

The spelling of 8138256481 in words is "eight billion, one hundred thirty-eight million, two hundred fifty-six thousand, four hundred eighty-one".