66431867 has 4 divisors (see below), whose sum is σ = 67520976. Its totient is φ = 65342760.

The previous prime is 66431863. The next prime is 66431879. The reversal of 66431867 is 76813466.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66431867 - 2² = 66431863 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66431863) 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 in 3 ways as a sum of consecutive naturals, for example, 544463 + ... + 544584.

It is an arithmetic number, because the mean of its divisors is an integer number (16880244).

Almost surely, 2^66431867 is an apocalyptic number.

66431867 is a deficient number, since it is larger than the sum of its proper divisors (1089109).

66431867 is a wasteful number, since it uses less digits than its factorization.

66431867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1089108.

The product of its digits is 145152, while the sum is 41.

The square root of 66431867 is about 8150.5746423182. The cubic root of 66431867 is about 405.0035400798.

The spelling of 66431867 in words is "sixty-six million, four hundred thirty-one thousand, eight hundred sixty-seven".