66443821751 has 16 divisors (see below), whose sum is σ = 72353961504. Its totient is φ = 60770863104.

The previous prime is 66443821739. The next prime is 66443821753. The reversal of 66443821751 is 15712834466.

It is a cyclic number.

It is not a de Polignac number, because 66443821751 - 2⁶ = 66443821687 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66443821696 and 66443821705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66443821753) 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, 86690 + ... + 374703.

It is an arithmetic number, because the mean of its divisors is an integer number (4522122594).

Almost surely, 2^66443821751 is an apocalyptic number.

66443821751 is a deficient number, since it is larger than the sum of its proper divisors (5910139753).

66443821751 is a wasteful number, since it uses less digits than its factorization.

66443821751 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 461650.

The product of its digits is 967680, while the sum is 47.

The spelling of 66443821751 in words is "sixty-six billion, four hundred forty-three million, eight hundred twenty-one thousand, seven hundred fifty-one".