66811471 has 2 divisors, whose sum is σ = 66811472. Its totient is φ = 66811470.

The previous prime is 66811463. The next prime is 66811517. The reversal of 66811471 is 17411866.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66811471 - 2³ = 66811463 is a prime.

It is a super-3 number, since 3×66811471³ (a number of 24 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66811421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33405735 + 33405736.

It is an arithmetic number, because the mean of its divisors is an integer number (33405736).

Almost surely, 2^66811471 is an apocalyptic number.

66811471 is a deficient number, since it is larger than the sum of its proper divisors (1).

66811471 is an equidigital number, since it uses as much as digits as its factorization.

66811471 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 34.

The square root of 66811471 is about 8173.8284175777. The cubic root of 66811471 is about 405.7734971404.

The spelling of 66811471 in words is "sixty-six million, eight hundred eleven thousand, four hundred seventy-one".