66389471 has 4 divisors (see below), whose sum is σ = 70294752. Its totient is φ = 62484192.

The previous prime is 66389447. The next prime is 66389501. The reversal of 66389471 is 17498366.

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 66389471 - 2²² = 62195167 is a prime.

It is a super-3 number, since 3×66389471³ (a number of 24 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66389441) 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 3 ways as a sum of consecutive naturals, for example, 1952615 + ... + 1952648.

It is an arithmetic number, because the mean of its divisors is an integer number (17573688).

Almost surely, 2^66389471 is an apocalyptic number.

66389471 is a deficient number, since it is larger than the sum of its proper divisors (3905281).

66389471 is a wasteful number, since it uses less digits than its factorization.

66389471 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3905280.

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

The square root of 66389471 is about 8147.9734290190. The cubic root of 66389471 is about 404.9173656536.

The spelling of 66389471 in words is "sixty-six million, three hundred eighty-nine thousand, four hundred seventy-one".