65173981 has 2 divisors, whose sum is σ = 65173982. Its totient is φ = 65173980.

The previous prime is 65173957. The next prime is 65174017. The reversal of 65173981 is 18937156.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59814756 + 5359225 = 7734^2 + 2315^2 .

It is a cyclic number.

It is not a de Polignac number, because 65173981 - 2¹¹ = 65171933 is a prime.

It is a super-2 number, since 2×65173981² = 8495295598776722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65173931) 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, 32586990 + 32586991.

It is an arithmetic number, because the mean of its divisors is an integer number (32586991).

Almost surely, 2^65173981 is an apocalyptic number.

It is an amenable number.

65173981 is a deficient number, since it is larger than the sum of its proper divisors (1).

65173981 is an equidigital number, since it uses as much as digits as its factorization.

65173981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 45360, while the sum is 40.

The square root of 65173981 is about 8073.0403814176. The cubic root of 65173981 is about 402.4309895445.

The spelling of 65173981 in words is "sixty-five million, one hundred seventy-three thousand, nine hundred eighty-one".