66604201061 has 2 divisors, whose sum is σ = 66604201062. Its totient is φ = 66604201060.

The previous prime is 66604201049. The next prime is 66604201099. The reversal of 66604201061 is 16010240666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65897970436 + 706230625 = 256706^2 + 26575^2 .

It is a cyclic number.

It is not a de Polignac number, because 66604201061 - 2¹⁴ = 66604184677 is a prime.

It is a super-2 number, since 2×66604201061² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66604201361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33302100530 + 33302100531.

It is an arithmetic number, because the mean of its divisors is an integer number (33302100531).

Almost surely, 2^66604201061 is an apocalyptic number.

It is an amenable number.

66604201061 is a deficient number, since it is larger than the sum of its proper divisors (1).

66604201061 is an equidigital number, since it uses as much as digits as its factorization.

66604201061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 32.

The spelling of 66604201061 in words is "sixty-six billion, six hundred four million, two hundred one thousand, sixty-one".