66471742481 has 4 divisors (see below), whose sum is σ = 66499709412. Its totient is φ = 66443775552.

The previous prime is 66471742417. The next prime is 66471742541. The reversal of 66471742481 is 18424717466.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18424717466 = 2 ⋅9212358733.

It can be written as a sum of positive squares in 2 ways, for example, as 49860657025 + 16611085456 = 223295^2 + 128884^2 .

It is a cyclic number.

It is not a de Polignac number, because 66471742481 - 2⁶ = 66471742417 is a prime.

It is a super-2 number, since 2×66471742481² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66471742781) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13979900 + ... + 13984653.

It is an arithmetic number, because the mean of its divisors is an integer number (16624927353).

Almost surely, 2^66471742481 is an apocalyptic number.

It is an amenable number.

66471742481 is a deficient number, since it is larger than the sum of its proper divisors (27966931).

66471742481 is a wasteful number, since it uses less digits than its factorization.

66471742481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27966930.

The product of its digits is 1806336, while the sum is 50.

The spelling of 66471742481 in words is "sixty-six billion, four hundred seventy-one million, seven hundred forty-two thousand, four hundred eighty-one".