66431863 has 2 divisors, whose sum is σ = 66431864. Its totient is φ = 66431862.

The previous prime is 66431857. The next prime is 66431879. The reversal of 66431863 is 36813466.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66431863 - 2¹³ = 66423671 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66431063) 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, 33215931 + 33215932.

It is an arithmetic number, because the mean of its divisors is an integer number (33215932).

Almost surely, 2^66431863 is an apocalyptic number.

66431863 is a deficient number, since it is larger than the sum of its proper divisors (1).

66431863 is an equidigital number, since it uses as much as digits as its factorization.

66431863 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 62208, while the sum is 37.

The square root of 66431863 is about 8150.5743969367. The cubic root of 66431863 is about 405.0035319511.

The spelling of 66431863 in words is "sixty-six million, four hundred thirty-one thousand, eight hundred sixty-three".