165974521441 has 2 divisors, whose sum is σ = 165974521442. Its totient is φ = 165974521440.

The previous prime is 165974521423. The next prime is 165974521483. The reversal of 165974521441 is 144125479561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 163442318400 + 2532203041 = 404280^2 + 50321^2 .

It is a cyclic number.

It is not a de Polignac number, because 165974521441 - 2¹¹ = 165974519393 is a prime.

It is not a weakly prime, because it can be changed into another prime (165974528441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82987260720 + 82987260721.

It is an arithmetic number, because the mean of its divisors is an integer number (82987260721).

Almost surely, 2^165974521441 is an apocalyptic number.

It is an amenable number.

165974521441 is a deficient number, since it is larger than the sum of its proper divisors (1).

165974521441 is an equidigital number, since it uses as much as digits as its factorization.

165974521441 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1209600, while the sum is 49.

The spelling of 165974521441 in words is "one hundred sixty-five billion, nine hundred seventy-four million, five hundred twenty-one thousand, four hundred forty-one".