165506641 has 2 divisors, whose sum is σ = 165506642. Its totient is φ = 165506640.

The previous prime is 165506633. The next prime is 165506687. The reversal of 165506641 is 146605561.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 120670225 + 44836416 = 10985^2 + 6696^2 .

It is an emirp because it is prime and its reverse (146605561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 165506641 - 2³ = 165506633 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 165506597 and 165506606.

It is not a weakly prime, because it can be changed into another prime (165506141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82753320 + 82753321.

It is an arithmetic number, because the mean of its divisors is an integer number (82753321).

Almost surely, 2^165506641 is an apocalyptic number.

It is an amenable number.

165506641 is a deficient number, since it is larger than the sum of its proper divisors (1).

165506641 is an equidigital number, since it uses as much as digits as its factorization.

165506641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 165506641 is about 12864.9384374742. The cubic root of 165506641 is about 549.0414610090.

The spelling of 165506641 in words is "one hundred sixty-five million, five hundred six thousand, six hundred forty-one".