66431879 has 2 divisors, whose sum is σ = 66431880. Its totient is φ = 66431878.

The previous prime is 66431863. The next prime is 66431917. The reversal of 66431879 is 97813466.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66431879 - 2⁴ = 66431863 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 (66431819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33215939 + 33215940.

It is an arithmetic number, because the mean of its divisors is an integer number (33215940).

Almost surely, 2^66431879 is an apocalyptic number.

66431879 is a deficient number, since it is larger than the sum of its proper divisors (1).

66431879 is an equidigital number, since it uses as much as digits as its factorization.

66431879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 217728, while the sum is 44.

The square root of 66431879 is about 8150.5753784626. The cubic root of 66431879 is about 405.0035644659.

The spelling of 66431879 in words is "sixty-six million, four hundred thirty-one thousand, eight hundred seventy-nine".