66211807 has 2 divisors, whose sum is σ = 66211808. Its totient is φ = 66211806.

The previous prime is 66211801. The next prime is 66211823. The reversal of 66211807 is 70811266.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66211807 - 2¹⁵ = 66179039 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66211801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33105903 + 33105904.

It is an arithmetic number, because the mean of its divisors is an integer number (33105904).

Almost surely, 2^66211807 is an apocalyptic number.

66211807 is a deficient number, since it is larger than the sum of its proper divisors (1).

66211807 is an equidigital number, since it uses as much as digits as its factorization.

66211807 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 66211807 is about 8137.0637824709. The cubic root of 66211807 is about 404.5558449425. Note that the first 3 decimals are identical.

The spelling of 66211807 in words is "sixty-six million, two hundred eleven thousand, eight hundred seven".