66144161 has 4 divisors (see below), whose sum is σ = 70035012. Its totient is φ = 62253312.

The previous prime is 66144121. The next prime is 66144163. The reversal of 66144161 is 16144166.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 39929761 + 26214400 = 6319^2 + 5120^2 .

It is a cyclic number.

It is not a de Polignac number, because 66144161 - 2¹⁴ = 66127777 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66144163) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1945400 + ... + 1945433.

It is an arithmetic number, because the mean of its divisors is an integer number (17508753).

Almost surely, 2^66144161 is an apocalyptic number.

It is an amenable number.

66144161 is a deficient number, since it is larger than the sum of its proper divisors (3890851).

66144161 is a wasteful number, since it uses less digits than its factorization.

66144161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3890850.

The product of its digits is 3456, while the sum is 29.

The square root of 66144161 is about 8132.9060611813. The cubic root of 66144161 is about 404.4180250630.

The spelling of 66144161 in words is "sixty-six million, one hundred forty-four thousand, one hundred sixty-one".