66946571 has 4 divisors (see below), whose sum is σ = 68503512. Its totient is φ = 65389632.

The previous prime is 66946567. The next prime is 66946573. The reversal of 66946571 is 17564966.

It is a happy number.

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 66946571 - 2² = 66946567 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66946573) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 778406 + ... + 778491.

It is an arithmetic number, because the mean of its divisors is an integer number (17125878).

Almost surely, 2^66946571 is an apocalyptic number.

66946571 is a deficient number, since it is larger than the sum of its proper divisors (1556941).

66946571 is a wasteful number, since it uses less digits than its factorization.

66946571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1556940.

The product of its digits is 272160, while the sum is 44.

The square root of 66946571 is about 8182.0884253349. The cubic root of 66946571 is about 406.0468189191.

The spelling of 66946571 in words is "sixty-six million, nine hundred forty-six thousand, five hundred seventy-one".