66455543321 has 4 divisors (see below), whose sum is σ = 66461911332. Its totient is φ = 66449175312.

The previous prime is 66455543317. The next prime is 66455543359. The reversal of 66455543321 is 12334555466.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 65956512400 + 499030921 = 256820^2 + 22339^2 .

It is a cyclic number.

It is not a de Polignac number, because 66455543321 - 2² = 66455543317 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66455543521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3168326 + ... + 3189231.

It is an arithmetic number, because the mean of its divisors is an integer number (16615477833).

Almost surely, 2^66455543321 is an apocalyptic number.

It is an amenable number.

66455543321 is a deficient number, since it is larger than the sum of its proper divisors (6368011).

66455543321 is a wasteful number, since it uses less digits than its factorization.

66455543321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6368010.

The product of its digits is 1296000, while the sum is 44.

The spelling of 66455543321 in words is "sixty-six billion, four hundred fifty-five million, five hundred forty-three thousand, three hundred twenty-one".