66077742481 has 4 divisors (see below), whose sum is σ = 66158227764. Its totient is φ = 65997257200.

The previous prime is 66077742469. The next prime is 66077742503. The reversal of 66077742481 is 18424777066.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18424777066 = 2 ⋅9212388533.

It can be written as a sum of positive squares in 2 ways, for example, as 26119731456 + 39958011025 = 161616^2 + 199895^2 .

It is a cyclic number.

It is not a de Polignac number, because 66077742481 - 2¹¹ = 66077740433 is a prime.

It is a super-2 number, since 2×66077742481² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66077749481) 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 in 3 ways as a sum of consecutive naturals, for example, 40241410 + ... + 40243051.

It is an arithmetic number, because the mean of its divisors is an integer number (16539556941).

Almost surely, 2^66077742481 is an apocalyptic number.

It is an amenable number.

66077742481 is a deficient number, since it is larger than the sum of its proper divisors (80485283).

66077742481 is an equidigital number, since it uses as much as digits as its factorization.

66077742481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80485282.

The product of its (nonzero) digits is 3161088, while the sum is 52.

The spelling of 66077742481 in words is "sixty-six billion, seventy-seven million, seven hundred forty-two thousand, four hundred eighty-one".