165919601 has 2 divisors, whose sum is σ = 165919602. Its totient is φ = 165919600.

The previous prime is 165919577. The next prime is 165919603. The reversal of 165919601 is 106919561.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 147865600 + 18054001 = 12160^2 + 4249^2 .

It is a cyclic number.

It is not a de Polignac number, because 165919601 - 2²² = 161725297 is a prime.

Together with 165919603, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_9287372 and since 165919601 and 9287372 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (165919603) 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, 82959800 + 82959801.

It is an arithmetic number, because the mean of its divisors is an integer number (82959801).

Almost surely, 2^165919601 is an apocalyptic number.

It is an amenable number.

165919601 is a deficient number, since it is larger than the sum of its proper divisors (1).

165919601 is an equidigital number, since it uses as much as digits as its factorization.

165919601 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14580, while the sum is 38.

The square root of 165919601 is about 12880.9782625389. The cubic root of 165919601 is about 549.4977243674.

The spelling of 165919601 in words is "one hundred sixty-five million, nine hundred nineteen thousand, six hundred one".