66571155481 has 2 divisors, whose sum is σ = 66571155482. Its totient is φ = 66571155480.

The previous prime is 66571155473. The next prime is 66571155487. The reversal of 66571155481 is 18455117566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65456664025 + 1114491456 = 255845^2 + 33384^2 .

It is a cyclic number.

It is not a de Polignac number, because 66571155481 - 2³ = 66571155473 is a prime.

It is a super-2 number, since 2×66571155481² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66571155487) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33285577740 + 33285577741.

It is an arithmetic number, because the mean of its divisors is an integer number (33285577741).

Almost surely, 2^66571155481 is an apocalyptic number.

It is an amenable number.

66571155481 is a deficient number, since it is larger than the sum of its proper divisors (1).

66571155481 is an equidigital number, since it uses as much as digits as its factorization.

66571155481 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1008000, while the sum is 49.

The spelling of 66571155481 in words is "sixty-six billion, five hundred seventy-one million, one hundred fifty-five thousand, four hundred eighty-one".