66219771 has 8 divisors (see below), whose sum is σ = 89789760. Its totient is φ = 43398152.

The previous prime is 66219761. The next prime is 66219779. The reversal of 66219771 is 17791266.

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 66219771 - 2⁶ = 66219707 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66219779) 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 7 ways as a sum of consecutive naturals, for example, 186885 + ... + 187238.

It is an arithmetic number, because the mean of its divisors is an integer number (11223720).

Almost surely, 2^66219771 is an apocalyptic number.

66219771 is a deficient number, since it is larger than the sum of its proper divisors (23569989).

66219771 is a wasteful number, since it uses less digits than its factorization.

66219771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 374185.

The product of its digits is 31752, while the sum is 39.

The square root of 66219771 is about 8137.5531334671. The cubic root of 66219771 is about 404.5720643738.

The spelling of 66219771 in words is "sixty-six million, two hundred nineteen thousand, seven hundred seventy-one".