66814385 has 12 divisors (see below), whose sum is σ = 88129524. Its totient is φ = 48591840.

The previous prime is 66814367. The next prime is 66814387. The reversal of 66814385 is 58341866.

It can be written as a sum of positive squares in 2 ways, for example, as 37405456 + 29408929 = 6116^2 + 5423^2 .

It is not a de Polignac number, because 66814385 - 2⁸ = 66814129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66814387) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 54614 + ... + 55823.

It is an arithmetic number, because the mean of its divisors is an integer number (7344127).

Almost surely, 2^66814385 is an apocalyptic number.

It is an amenable number.

66814385 is a deficient number, since it is larger than the sum of its proper divisors (21315139).

66814385 is a wasteful number, since it uses less digits than its factorization.

66814385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110464 (or 110453 counting only the distinct ones).

The product of its digits is 138240, while the sum is 41.

The square root of 66814385 is about 8174.0066674795. The cubic root of 66814385 is about 405.7793963608.

The spelling of 66814385 in words is "sixty-six million, eight hundred fourteen thousand, three hundred eighty-five".