66210643 has 2 divisors, whose sum is σ = 66210644. Its totient is φ = 66210642.

The previous prime is 66210623. The next prime is 66210647. The reversal of 66210643 is 34601266.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66210643 is a prime.

It is not a weakly prime, because it can be changed into another prime (66210647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33105321 + 33105322.

It is an arithmetic number, because the mean of its divisors is an integer number (33105322).

Almost surely, 2^66210643 is an apocalyptic number.

66210643 is a deficient number, since it is larger than the sum of its proper divisors (1).

66210643 is an equidigital number, since it uses as much as digits as its factorization.

66210643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 28.

The square root of 66210643 is about 8136.9922575851. The cubic root of 66210643 is about 404.5534742386.

The spelling of 66210643 in words is "sixty-six million, two hundred ten thousand, six hundred forty-three".