66061917 has 18 divisors (see below), whose sum is σ = 100714302. Its totient is φ = 41721264.

The previous prime is 66061901. The next prime is 66061921. The reversal of 66061917 is 71916066.

66061917 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 65512836 + 549081 = 8094^2 + 741^2 .

It is not a de Polignac number, because 66061917 - 2⁴ = 66061901 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66061927) 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 in 17 ways as a sum of consecutive naturals, for example, 6918 + ... + 13415.

It is an arithmetic number, because the mean of its divisors is an integer number (5595239).

Almost surely, 2^66061917 is an apocalyptic number.

It is an amenable number.

66061917 is a deficient number, since it is larger than the sum of its proper divisors (34652385).

66061917 is a wasteful number, since it uses less digits than its factorization.

66061917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20377 (or 20355 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The square root of 66061917 is about 8127.8482392328. The cubic root of 66061917 is about 404.2503370379.

The spelling of 66061917 in words is "sixty-six million, sixty-one thousand, nine hundred seventeen".