66431287 has 8 divisors (see below), whose sum is σ = 72106496. Its totient is φ = 60836832.

The previous prime is 66431273. The next prime is 66431303. The reversal of 66431287 is 78213466.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66431287 - 2¹¹ = 66429239 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66431587) 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 in 7 ways as a sum of consecutive naturals, for example, 18468 + ... + 21769.

It is an arithmetic number, because the mean of its divisors is an integer number (9013312).

Almost surely, 2^66431287 is an apocalyptic number.

66431287 is a deficient number, since it is larger than the sum of its proper divisors (5675209).

66431287 is a wasteful number, since it uses less digits than its factorization.

66431287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40377.

The product of its digits is 48384, while the sum is 37.

The square root of 66431287 is about 8150.5390619271. The cubic root of 66431287 is about 405.0023614149.

The spelling of 66431287 in words is "sixty-six million, four hundred thirty-one thousand, two hundred eighty-seven".