66651071 has 2 divisors, whose sum is σ = 66651072. Its totient is φ = 66651070.

The previous prime is 66651047. The next prime is 66651073. The reversal of 66651071 is 17015666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66651071 - 2⁶ = 66651007 is a prime.

Together with 66651073, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66651073) 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 as a sum of consecutive naturals, namely, 33325535 + 33325536.

It is an arithmetic number, because the mean of its divisors is an integer number (33325536).

Almost surely, 2^66651071 is an apocalyptic number.

66651071 is a deficient number, since it is larger than the sum of its proper divisors (1).

66651071 is an equidigital number, since it uses as much as digits as its factorization.

66651071 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 66651071 is about 8164.0107177784. The cubic root of 66651071 is about 405.4485119074.

The spelling of 66651071 in words is "sixty-six million, six hundred fifty-one thousand, seventy-one".