165821650133 has 2 divisors, whose sum is σ = 165821650134. Its totient is φ = 165821650132.

The previous prime is 165821650117. The next prime is 165821650151. The reversal of 165821650133 is 331056128561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 147645757009 + 18175893124 = 384247^2 + 134818^2 .

It is a cyclic number.

It is not a de Polignac number, because 165821650133 - 2⁴ = 165821650117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165821650153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82910825066 + 82910825067.

It is an arithmetic number, because the mean of its divisors is an integer number (82910825067).

Almost surely, 2^165821650133 is an apocalyptic number.

It is an amenable number.

165821650133 is a deficient number, since it is larger than the sum of its proper divisors (1).

165821650133 is an equidigital number, since it uses as much as digits as its factorization.

165821650133 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 129600, while the sum is 41.

Adding to 165821650133 its reverse (331056128561), we get a palindrome (496877778694).

The spelling of 165821650133 in words is "one hundred sixty-five billion, eight hundred twenty-one million, six hundred fifty thousand, one hundred thirty-three".