856646171653 has 2 divisors, whose sum is σ = 856646171654. Its totient is φ = 856646171652.

The previous prime is 856646171617. The next prime is 856646171687. The reversal of 856646171653 is 356171646658.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 854779758849 + 1866412804 = 924543^2 + 43202^2 .

It is a cyclic number.

It is not a de Polignac number, because 856646171653 - 2¹⁷ = 856646040581 is a prime.

It is a super-2 number, since 2×856646171653² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (856646171603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428323085826 + 428323085827.

It is an arithmetic number, because the mean of its divisors is an integer number (428323085827).

Almost surely, 2^856646171653 is an apocalyptic number.

It is an amenable number.

856646171653 is a deficient number, since it is larger than the sum of its proper divisors (1).

856646171653 is an equidigital number, since it uses as much as digits as its factorization.

856646171653 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21772800, while the sum is 58.

The spelling of 856646171653 in words is "eight hundred fifty-six billion, six hundred forty-six million, one hundred seventy-one thousand, six hundred fifty-three".