66321930991 has 16 divisors (see below), whose sum is σ = 69401884608. Its totient is φ = 63258624000.

The previous prime is 66321930971. The next prime is 66321931007. The reversal of 66321930991 is 19903912366.

It is a cyclic number.

It is not a de Polignac number, because 66321930991 - 2⁷ = 66321930863 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 (66321930931) 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, 13811791 + ... + 13816591.

It is an arithmetic number, because the mean of its divisors is an integer number (4337617788).

Almost surely, 2^66321930991 is an apocalyptic number.

66321930991 is a deficient number, since it is larger than the sum of its proper divisors (3079953617).

66321930991 is a wasteful number, since it uses less digits than its factorization.

66321930991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6402.

The product of its (nonzero) digits is 472392, while the sum is 49.

The spelling of 66321930991 in words is "sixty-six billion, three hundred twenty-one million, nine hundred thirty thousand, nine hundred ninety-one".