165641617 has 2 divisors, whose sum is σ = 165641618. Its totient is φ = 165641616.

The previous prime is 165641569. The next prime is 165641647. The reversal of 165641617 is 716146561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 148864401 + 16777216 = 12201^2 + 4096^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165641617 is a prime.

It is not a weakly prime, because it can be changed into another prime (165641647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82820808 + 82820809.

It is an arithmetic number, because the mean of its divisors is an integer number (82820809).

Almost surely, 2^165641617 is an apocalyptic number.

It is an amenable number.

165641617 is a deficient number, since it is larger than the sum of its proper divisors (1).

165641617 is an equidigital number, since it uses as much as digits as its factorization.

165641617 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30240, while the sum is 37.

The square root of 165641617 is about 12870.1832543286. The cubic root of 165641617 is about 549.1906741226.

It can be divided in two parts, 16564 and 1617, that added together give a palindrome (18181).

The spelling of 165641617 in words is "one hundred sixty-five million, six hundred forty-one thousand, six hundred seventeen".