66180792921 has 16 divisors (see below), whose sum is σ = 90539413440. Its totient is φ = 42974830080.

The previous prime is 66180792911. The next prime is 66180792949. The reversal of 66180792921 is 12929708166.

It is not a de Polignac number, because 66180792921 - 2⁶ = 66180792857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66180792911) 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 15 ways as a sum of consecutive naturals, for example, 358480 + ... + 510753.

It is an arithmetic number, because the mean of its divisors is an integer number (5658713340).

Almost surely, 2^66180792921 is an apocalyptic number.

It is an amenable number.

66180792921 is a deficient number, since it is larger than the sum of its proper divisors (24358620519).

66180792921 is a wasteful number, since it uses less digits than its factorization.

66180792921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 869896.

The product of its (nonzero) digits is 653184, while the sum is 51.

The spelling of 66180792921 in words is "sixty-six billion, one hundred eighty million, seven hundred ninety-two thousand, nine hundred twenty-one".