66823871 has 2 divisors, whose sum is σ = 66823872. Its totient is φ = 66823870.

The previous prime is 66823837. The next prime is 66823873. The reversal of 66823871 is 17832866.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66823871 is a prime.

Together with 66823873, 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 (66823873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33411935 + 33411936.

It is an arithmetic number, because the mean of its divisors is an integer number (33411936).

Almost surely, 2^66823871 is an apocalyptic number.

66823871 is a deficient number, since it is larger than the sum of its proper divisors (1).

66823871 is an equidigital number, since it uses as much as digits as its factorization.

66823871 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96768, while the sum is 41.

The square root of 66823871 is about 8174.5869008776. The cubic root of 66823871 is about 405.7985990181.

The spelling of 66823871 in words is "sixty-six million, eight hundred twenty-three thousand, eight hundred seventy-one".