66204917 has 2 divisors, whose sum is σ = 66204918. Its totient is φ = 66204916.

The previous prime is 66204899. The next prime is 66204961. The reversal of 66204917 is 71940266.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 63138916 + 3066001 = 7946^2 + 1751^2 .

It is a cyclic number.

It is not a de Polignac number, because 66204917 - 2¹² = 66200821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66204977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33102458 + 33102459.

It is an arithmetic number, because the mean of its divisors is an integer number (33102459).

Almost surely, 2^66204917 is an apocalyptic number.

It is an amenable number.

66204917 is a deficient number, since it is larger than the sum of its proper divisors (1).

66204917 is an equidigital number, since it uses as much as digits as its factorization.

66204917 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 66204917 is about 8136.6404000668. The cubic root of 66204917 is about 404.5418117632.

The spelling of 66204917 in words is "sixty-six million, two hundred four thousand, nine hundred seventeen".