66655871 has 2 divisors, whose sum is σ = 66655872. Its totient is φ = 66655870.

The previous prime is 66655837. The next prime is 66655877. The reversal of 66655871 is 17855666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66655871 - 2⁶ = 66655807 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66655877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33327935 + 33327936.

It is an arithmetic number, because the mean of its divisors is an integer number (33327936).

Almost surely, 2^66655871 is an apocalyptic number.

66655871 is a deficient number, since it is larger than the sum of its proper divisors (1).

66655871 is an equidigital number, since it uses as much as digits as its factorization.

66655871 is an evil number, because the sum of its binary digits is even.

The product of its digits is 302400, while the sum is 44.

The square root of 66655871 is about 8164.3046856423. The cubic root of 66655871 is about 405.4582447149.

The spelling of 66655871 in words is "sixty-six million, six hundred fifty-five thousand, eight hundred seventy-one".