165825558881 has 2 divisors, whose sum is σ = 165825558882. Its totient is φ = 165825558880.

The previous prime is 165825558683. The next prime is 165825558893. The reversal of 165825558881 is 188855528561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 159527549281 + 6298009600 = 399409^2 + 79360^2 .

It is a cyclic number.

It is not a de Polignac number, because 165825558881 - 2¹⁸ = 165825296737 is a prime.

It is a super-2 number, since 2×165825558881² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (165825557881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82912779440 + 82912779441.

It is an arithmetic number, because the mean of its divisors is an integer number (82912779441).

Almost surely, 2^165825558881 is an apocalyptic number.

It is an amenable number.

165825558881 is a deficient number, since it is larger than the sum of its proper divisors (1).

165825558881 is an equidigital number, since it uses as much as digits as its factorization.

165825558881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30720000, while the sum is 62.

The spelling of 165825558881 in words is "one hundred sixty-five billion, eight hundred twenty-five million, five hundred fifty-eight thousand, eight hundred eighty-one".