66073317921 has 16 divisors (see below), whose sum is σ = 105416120320. Its totient is φ = 40660503120.

The previous prime is 66073317911. The next prime is 66073317923. The reversal of 66073317921 is 12971337066.

66073317921 is a `hidden beast` number, since 6 + 607 + 3 + 3 + 17 + 9 + 21 = 666.

It is not a de Polignac number, because 66073317921 - 2⁶ = 66073317857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66073317923) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 94121185 + ... + 94121886.

It is an arithmetic number, because the mean of its divisors is an integer number (6588507520).

Almost surely, 2^66073317921 is an apocalyptic number.

It is an amenable number.

66073317921 is a deficient number, since it is larger than the sum of its proper divisors (39342802399).

66073317921 is a wasteful number, since it uses less digits than its factorization.

66073317921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188243093 (or 188243087 counting only the distinct ones).

The product of its (nonzero) digits is 285768, while the sum is 45.

The spelling of 66073317921 in words is "sixty-six billion, seventy-three million, three hundred seventeen thousand, nine hundred twenty-one".