8506173721 has 2 divisors, whose sum is σ = 8506173722. Its totient is φ = 8506173720.

The previous prime is 8506173701. The next prime is 8506173749. The reversal of 8506173721 is 1273716058.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7998798096 + 507375625 = 89436^2 + 22525^2 .

It is a cyclic number.

It is not a de Polignac number, because 8506173721 - 2¹⁵ = 8506140953 is a prime.

It is not a weakly prime, because it can be changed into another prime (8506173701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4253086860 + 4253086861.

It is an arithmetic number, because the mean of its divisors is an integer number (4253086861).

Almost surely, 2^8506173721 is an apocalyptic number.

It is an amenable number.

8506173721 is a deficient number, since it is larger than the sum of its proper divisors (1).

8506173721 is an equidigital number, since it uses as much as digits as its factorization.

8506173721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 70560, while the sum is 40.

The square root of 8506173721 is about 92228.9201986015. The cubic root of 8506173721 is about 2041.3215294181.

Adding to 8506173721 its reverse (1273716058), we get a palindrome (9779889779).

The spelling of 8506173721 in words is "eight billion, five hundred six million, one hundred seventy-three thousand, seven hundred twenty-one".