166110561550121 has 2 divisors, whose sum is σ = 166110561550122. Its totient is φ = 166110561550120.

The previous prime is 166110561550103. The next prime is 166110561550181. The reversal of 166110561550121 is 121055165011661.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 166108792422400 + 1769127721 = 12888320^2 + 42061^2 .

It is a cyclic number.

It is not a de Polignac number, because 166110561550121 - 2²² = 166110557355817 is a prime.

It is a super-2 number, since 2×166110561550121² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (166110561550181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83055280775060 + 83055280775061.

It is an arithmetic number, because the mean of its divisors is an integer number (83055280775061).

Almost surely, 2^{166110561550121} is an apocalyptic number.

It is an amenable number.

166110561550121 is a deficient number, since it is larger than the sum of its proper divisors (1).

166110561550121 is an equidigital number, since it uses as much as digits as its factorization.

166110561550121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54000, while the sum is 41.

The spelling of 166110561550121 in words is "one hundred sixty-six trillion, one hundred ten billion, five hundred sixty-one million, five hundred fifty thousand, one hundred twenty-one".