66144067669 has 2 divisors, whose sum is σ = 66144067670. Its totient is φ = 66144067668.

The previous prime is 66144067607. The next prime is 66144067679. The reversal of 66144067669 is 96676044166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46610651025 + 19533416644 = 215895^2 + 139762^2 .

It is a cyclic number.

It is not a de Polignac number, because 66144067669 - 2²⁹ = 65607196757 is a prime.

It is a super-2 number, since 2×66144067669² (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 (66144067679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33072033834 + 33072033835.

It is an arithmetic number, because the mean of its divisors is an integer number (33072033835).

Almost surely, 2^66144067669 is an apocalyptic number.

It is an amenable number.

66144067669 is a deficient number, since it is larger than the sum of its proper divisors (1).

66144067669 is an equidigital number, since it uses as much as digits as its factorization.

66144067669 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7838208, while the sum is 55.

The spelling of 66144067669 in words is "sixty-six billion, one hundred forty-four million, sixty-seven thousand, six hundred sixty-nine".