66197190921 has 8 divisors (see below), whose sum is σ = 88335690240. Its totient is φ = 44095076112.

The previous prime is 66197190893. The next prime is 66197190931. The reversal of 66197190921 is 12909179166.

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

It is not a de Polignac number, because 66197190921 - 2¹⁰ = 66197189897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66197190931) 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, 9091881 + ... + 9099158.

It is an arithmetic number, because the mean of its divisors is an integer number (11041961280).

Almost surely, 2^66197190921 is an apocalyptic number.

It is an amenable number.

66197190921 is a deficient number, since it is larger than the sum of its proper divisors (22138499319).

66197190921 is a wasteful number, since it uses less digits than its factorization.

66197190921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18192255.

The product of its (nonzero) digits is 367416, while the sum is 51.

The spelling of 66197190921 in words is "sixty-six billion, one hundred ninety-seven million, one hundred ninety thousand, nine hundred twenty-one".