66687364609 has 2 divisors, whose sum is σ = 66687364610. Its totient is φ = 66687364608.

The previous prime is 66687364561. The next prime is 66687364619. The reversal of 66687364609 is 90646378666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65483274609 + 1204090000 = 255897^2 + 34700^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66687364609 is a prime.

It is not a weakly prime, because it can be changed into another prime (66687364619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33343682304 + 33343682305.

It is an arithmetic number, because the mean of its divisors is an integer number (33343682305).

Almost surely, 2^66687364609 is an apocalyptic number.

It is an amenable number.

66687364609 is a deficient number, since it is larger than the sum of its proper divisors (1).

66687364609 is an equidigital number, since it uses as much as digits as its factorization.

66687364609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 47029248, while the sum is 61.

The spelling of 66687364609 in words is "sixty-six billion, six hundred eighty-seven million, three hundred sixty-four thousand, six hundred nine".