66172755269 has 2 divisors, whose sum is σ = 66172755270. Its totient is φ = 66172755268.

The previous prime is 66172755251. The next prime is 66172755371. The reversal of 66172755269 is 96255727166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64661878369 + 1510876900 = 254287^2 + 38870^2 .

It is a cyclic number.

It is not a de Polignac number, because 66172755269 - 2¹⁶ = 66172689733 is a prime.

It is a super-2 number, since 2×66172755269² (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 (66172755239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33086377634 + 33086377635.

It is an arithmetic number, because the mean of its divisors is an integer number (33086377635).

Almost surely, 2^66172755269 is an apocalyptic number.

It is an amenable number.

66172755269 is a deficient number, since it is larger than the sum of its proper divisors (1).

66172755269 is an equidigital number, since it uses as much as digits as its factorization.

66172755269 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9525600, while the sum is 56.

The spelling of 66172755269 in words is "sixty-six billion, one hundred seventy-two million, seven hundred fifty-five thousand, two hundred sixty-nine".