66919917 has 8 divisors (see below), whose sum is σ = 92104960. Its totient is φ = 43174080.

The previous prime is 66919891. The next prime is 66919933. The reversal of 66919917 is 71991966.

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

It is not a de Polignac number, because 66919917 - 2⁷ = 66919789 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 (66919967) 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, 359692 + ... + 359877.

It is an arithmetic number, because the mean of its divisors is an integer number (11513120).

Almost surely, 2^66919917 is an apocalyptic number.

It is an amenable number.

66919917 is a deficient number, since it is larger than the sum of its proper divisors (25185043).

66919917 is a wasteful number, since it uses less digits than its factorization.

66919917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 719603.

The product of its digits is 183708, while the sum is 48.

The square root of 66919917 is about 8180.4594614239. The cubic root of 66919917 is about 405.9929241570.

The spelling of 66919917 in words is "sixty-six million, nine hundred nineteen thousand, nine hundred seventeen".