8137844681 has 2 divisors, whose sum is σ = 8137844682. Its totient is φ = 8137844680.

The previous prime is 8137844641. The next prime is 8137844719. The reversal of 8137844681 is 1864487318.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6996486025 + 1141358656 = 83645^2 + 33784^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8137844681 is a prime.

It is a super-3 number, since 3×8137844681³ (a number of 31 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (8137844641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4068922340 + 4068922341.

It is an arithmetic number, because the mean of its divisors is an integer number (4068922341).

Almost surely, 2^8137844681 is an apocalyptic number.

It is an amenable number.

8137844681 is a deficient number, since it is larger than the sum of its proper divisors (1).

8137844681 is an equidigital number, since it uses as much as digits as its factorization.

8137844681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1032192, while the sum is 50.

The square root of 8137844681 is about 90210.0032202638. The cubic root of 8137844681 is about 2011.4217049099.

The spelling of 8137844681 in words is "eight billion, one hundred thirty-seven million, eight hundred forty-four thousand, six hundred eighty-one".