66391271 has 8 divisors (see below), whose sum is σ = 69746400. Its totient is φ = 63075232.

The previous prime is 66391267. The next prime is 66391289. The reversal of 66391271 is 17219366.

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 66391271 - 2² = 66391267 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 (66391201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6260 + ... + 13113.

It is an arithmetic number, because the mean of its divisors is an integer number (8718300).

Almost surely, 2^66391271 is an apocalyptic number.

66391271 is a deficient number, since it is larger than the sum of its proper divisors (3355129).

66391271 is a wasteful number, since it uses less digits than its factorization.

66391271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19545.

The product of its digits is 13608, while the sum is 35.

The square root of 66391271 is about 8148.0838851843. The cubic root of 66391271 is about 404.9210250927.

The spelling of 66391271 in words is "sixty-six million, three hundred ninety-one thousand, two hundred seventy-one".