166556417 has 2 divisors, whose sum is σ = 166556418. Its totient is φ = 166556416.

The previous prime is 166556407. The next prime is 166556419. The reversal of 166556417 is 714655661.

166556417 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 159163456 + 7392961 = 12616^2 + 2719^2 .

It is a cyclic number.

It is not a de Polignac number, because 166556417 - 2⁶ = 166556353 is a prime.

Together with 166556419, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (166556419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83278208 + 83278209.

It is an arithmetic number, because the mean of its divisors is an integer number (83278209).

Almost surely, 2^166556417 is an apocalyptic number.

It is an amenable number.

166556417 is a deficient number, since it is larger than the sum of its proper divisors (1).

166556417 is an equidigital number, since it uses as much as digits as its factorization.

166556417 is an evil number, because the sum of its binary digits is even.

The product of its digits is 151200, while the sum is 41.

The square root of 166556417 is about 12905.6738297541. The cubic root of 166556417 is about 550.1998359232.

The spelling of 166556417 in words is "one hundred sixty-six million, five hundred fifty-six thousand, four hundred seventeen".