66539177909 has 2 divisors, whose sum is σ = 66539177910. Its totient is φ = 66539177908.

The previous prime is 66539177833. The next prime is 66539177927. The reversal of 66539177909 is 90977193566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66472183684 + 66994225 = 257822^2 + 8185^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66539177909 is a prime.

It is a super-2 number, since 2×66539177909² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66539177989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33269588954 + 33269588955.

It is an arithmetic number, because the mean of its divisors is an integer number (33269588955).

Almost surely, 2^66539177909 is an apocalyptic number.

It is an amenable number.

66539177909 is a deficient number, since it is larger than the sum of its proper divisors (1).

66539177909 is an equidigital number, since it uses as much as digits as its factorization.

66539177909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19289340, while the sum is 62.

The spelling of 66539177909 in words is "sixty-six billion, five hundred thirty-nine million, one hundred seventy-seven thousand, nine hundred nine".