165111430040261 has 2 divisors, whose sum is σ = 165111430040262. Its totient is φ = 165111430040260.

The previous prime is 165111430040243. The next prime is 165111430040269. The reversal of 165111430040261 is 162040034111561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 105685986776161 + 59425443264100 = 10280369^2 + 7708790^2 .

It is a cyclic number.

It is not a de Polignac number, because 165111430040261 - 2⁴² = 160713383529157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165111430040269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82555715020130 + 82555715020131.

It is an arithmetic number, because the mean of its divisors is an integer number (82555715020131).

Almost surely, 2^{165111430040261} is an apocalyptic number.

It is an amenable number.

165111430040261 is a deficient number, since it is larger than the sum of its proper divisors (1).

165111430040261 is an equidigital number, since it uses as much as digits as its factorization.

165111430040261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 35.

The spelling of 165111430040261 in words is "one hundred sixty-five trillion, one hundred eleven billion, four hundred thirty million, forty thousand, two hundred sixty-one".