66321443663 has 4 divisors (see below), whose sum is σ = 66325136640. Its totient is φ = 66317750688.

The previous prime is 66321443611. The next prime is 66321443689. The reversal of 66321443663 is 36634412366.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 36634412366 = 2 ⋅18317206183.

It is a cyclic number.

It is not a de Polignac number, because 66321443663 - 2¹⁰ = 66321442639 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 (66321443603) 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, 1819418 + ... + 1855511.

It is an arithmetic number, because the mean of its divisors is an integer number (16581284160).

Almost surely, 2^66321443663 is an apocalyptic number.

66321443663 is a deficient number, since it is larger than the sum of its proper divisors (3692977).

66321443663 is a wasteful number, since it uses less digits than its factorization.

66321443663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3692976.

The product of its digits is 1119744, while the sum is 44.

The spelling of 66321443663 in words is "sixty-six billion, three hundred twenty-one million, four hundred forty-three thousand, six hundred sixty-three".