166505436541 has 2 divisors, whose sum is σ = 166505436542. Its totient is φ = 166505436540.

The previous prime is 166505436529. The next prime is 166505436547. The reversal of 166505436541 is 145634505661.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 143448532516 + 23056904025 = 378746^2 + 151845^2 .

It is a cyclic number.

It is not a de Polignac number, because 166505436541 - 2³⁵ = 132145698173 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 166505436491 and 166505436500.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166505436547) 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, 83252718270 + 83252718271.

It is an arithmetic number, because the mean of its divisors is an integer number (83252718271).

Almost surely, 2^166505436541 is an apocalyptic number.

It is an amenable number.

166505436541 is a deficient number, since it is larger than the sum of its proper divisors (1).

166505436541 is an equidigital number, since it uses as much as digits as its factorization.

166505436541 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296000, while the sum is 46.

The spelling of 166505436541 in words is "one hundred sixty-six billion, five hundred five million, four hundred thirty-six thousand, five hundred forty-one".