66445145 has 16 divisors (see below), whose sum is σ = 86320080. Its totient is φ = 48808704.

The previous prime is 66445139. The next prime is 66445187. The reversal of 66445145 is 54154466.

It can be written as a sum of positive squares in 8 ways, for example, as 2876416 + 63568729 = 1696^2 + 7973^2 .

It is a cyclic number.

It is not a de Polignac number, because 66445145 - 2¹⁶ = 66379609 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10211 + ... + 15399.

It is an arithmetic number, because the mean of its divisors is an integer number (5395005).

Almost surely, 2^66445145 is an apocalyptic number.

66445145 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

66445145 is a deficient number, since it is larger than the sum of its proper divisors (19874935).

66445145 is a wasteful number, since it uses less digits than its factorization.

66445145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5404.

The product of its digits is 57600, while the sum is 35.

The square root of 66445145 is about 8151.3891454156. The cubic root of 66445145 is about 405.0305215021.

The spelling of 66445145 in words is "sixty-six million, four hundred forty-five thousand, one hundred forty-five".