66805921311 has 48 divisors (see below), whose sum is σ = 95647989600. Its totient is φ = 41418832896.

The previous prime is 66805921291. The next prime is 66805921327. The reversal of 66805921311 is 11312950866.

It is not a de Polignac number, because 66805921311 - 2¹⁰ = 66805920287 is a prime.

It is a super-2 number, since 2×66805921311² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66805921811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 11740155 + ... + 11745843.

It is an arithmetic number, because the mean of its divisors is an integer number (1992666450).

Almost surely, 2^66805921311 is an apocalyptic number.

66805921311 is a deficient number, since it is larger than the sum of its proper divisors (28842068289).

66805921311 is a wasteful number, since it uses less digits than its factorization.

66805921311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5880 (or 5837 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 42.

The spelling of 66805921311 in words is "sixty-six billion, eight hundred five million, nine hundred twenty-one thousand, three hundred eleven".