66919442671 has 2 divisors, whose sum is σ = 66919442672. Its totient is φ = 66919442670.

The previous prime is 66919442657. The next prime is 66919442699. The reversal of 66919442671 is 17624491966.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66919442671 - 2⁷ = 66919442543 is a prime.

It is a super-2 number, since 2×66919442671² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66919142671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33459721335 + 33459721336.

It is an arithmetic number, because the mean of its divisors is an integer number (33459721336).

Almost surely, 2^66919442671 is an apocalyptic number.

66919442671 is a deficient number, since it is larger than the sum of its proper divisors (1).

66919442671 is an equidigital number, since it uses as much as digits as its factorization.

66919442671 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3919104, while the sum is 55.

The spelling of 66919442671 in words is "sixty-six billion, nine hundred nineteen million, four hundred forty-two thousand, six hundred seventy-one".