171253981 has 2 divisors, whose sum is σ = 171253982. Its totient is φ = 171253980.

The previous prime is 171253967. The next prime is 171253997. The reversal of 171253981 is 189352171.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 126765081 + 44488900 = 11259^2 + 6670^2 .

It is a cyclic number.

It is not a de Polignac number, because 171253981 - 2⁵ = 171253949 is a prime.

It is a super-2 number, since 2×171253981² = 58655852016696722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 171253981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (171253921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85626990 + 85626991.

It is an arithmetic number, because the mean of its divisors is an integer number (85626991).

Almost surely, 2^171253981 is an apocalyptic number.

It is an amenable number.

171253981 is a deficient number, since it is larger than the sum of its proper divisors (1).

171253981 is an equidigital number, since it uses as much as digits as its factorization.

171253981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15120, while the sum is 37.

The square root of 171253981 is about 13086.4044336097. The cubic root of 171253981 is about 555.3245738291.

The spelling of 171253981 in words is "one hundred seventy-one million, two hundred fifty-three thousand, nine hundred eighty-one".