166111553 has 2 divisors, whose sum is σ = 166111554. Its totient is φ = 166111552.

The previous prime is 166111523. The next prime is 166111577. The reversal of 166111553 is 355111661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 140019889 + 26091664 = 11833^2 + 5108^2 .

It is an emirp because it is prime and its reverse (355111661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166111553 - 2¹² = 166107457 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (166111513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83055776 + 83055777.

It is an arithmetic number, because the mean of its divisors is an integer number (83055777).

Almost surely, 2^166111553 is an apocalyptic number.

It is an amenable number.

166111553 is a deficient number, since it is larger than the sum of its proper divisors (1).

166111553 is an equidigital number, since it uses as much as digits as its factorization.

166111553 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2700, while the sum is 29.

The square root of 166111553 is about 12888.4270956545. The cubic root of 166111553 is about 549.7095469152.

The spelling of 166111553 in words is "one hundred sixty-six million, one hundred eleven thousand, five hundred fifty-three".