8361273581 has 2 divisors, whose sum is σ = 8361273582. Its totient is φ = 8361273580.

The previous prime is 8361273577. The next prime is 8361273617. The reversal of 8361273581 is 1853721638.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7764253225 + 597020356 = 88115^2 + 24434^2 .

It is a cyclic number.

It is not a de Polignac number, because 8361273581 - 2² = 8361273577 is a prime.

It is a super-2 number, since 2×8361273581² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8361273511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4180636790 + 4180636791.

It is an arithmetic number, because the mean of its divisors is an integer number (4180636791).

Almost surely, 2^8361273581 is an apocalyptic number.

It is an amenable number.

8361273581 is a deficient number, since it is larger than the sum of its proper divisors (1).

8361273581 is an equidigital number, since it uses as much as digits as its factorization.

8361273581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 241920, while the sum is 44.

The square root of 8361273581 is about 91439.9998961067. Note that the first 3 decimals coincide. The cubic root of 8361273581 is about 2029.6639806371.

The spelling of 8361273581 in words is "eight billion, three hundred sixty-one million, two hundred seventy-three thousand, five hundred eighty-one".