66543161 has 2 divisors, whose sum is σ = 66543162. Its totient is φ = 66543160.

The previous prime is 66543157. The next prime is 66543167. The reversal of 66543161 is 16134566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 47183161 + 19360000 = 6869^2 + 4400^2 .

It is a cyclic number.

It is not a de Polignac number, because 66543161 - 2² = 66543157 is a prime.

It is equal to p_3926426 and since 66543161 and 3926426 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (66543167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33271580 + 33271581.

It is an arithmetic number, because the mean of its divisors is an integer number (33271581).

Almost surely, 2^66543161 is an apocalyptic number.

It is an amenable number.

66543161 is a deficient number, since it is larger than the sum of its proper divisors (1).

66543161 is an equidigital number, since it uses as much as digits as its factorization.

66543161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12960, while the sum is 32.

The square root of 66543161 is about 8157.3991565940. The cubic root of 66543161 is about 405.2295827818.

The spelling of 66543161 in words is "sixty-six million, five hundred forty-three thousand, one hundred sixty-one".