171617056981 has 2 divisors, whose sum is σ = 171617056982. Its totient is φ = 171617056980.

The previous prime is 171617056967. The next prime is 171617057009. The reversal of 171617056981 is 189650716171.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 157410562500 + 14206494481 = 396750^2 + 119191^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-171617056981 is a prime.

It is a super-2 number, since 2×171617056981² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (171617056781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85808528490 + 85808528491.

It is an arithmetic number, because the mean of its divisors is an integer number (85808528491).

Almost surely, 2^171617056981 is an apocalyptic number.

It is an amenable number.

171617056981 is a deficient number, since it is larger than the sum of its proper divisors (1).

171617056981 is an equidigital number, since it uses as much as digits as its factorization.

171617056981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 635040, while the sum is 52.

The spelling of 171617056981 in words is "one hundred seventy-one billion, six hundred seventeen million, fifty-six thousand, nine hundred eighty-one".