663955540543 has 4 divisors (see below), whose sum is σ = 681900284920. Its totient is φ = 646010796168.

The previous prime is 663955540513. The next prime is 663955540579. The reversal of 663955540543 is 345045559366.

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

It is a cyclic number.

It is not a de Polignac number, because 663955540543 - 2¹⁷ = 663955409471 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 (663955540513) 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, 8972372133 + ... + 8972372206.

It is an arithmetic number, because the mean of its divisors is an integer number (170475071230).

Almost surely, 2^663955540543 is an apocalyptic number.

663955540543 is a deficient number, since it is larger than the sum of its proper divisors (17944744377).

663955540543 is a wasteful number, since it uses less digits than its factorization.

663955540543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17944744376.

The product of its (nonzero) digits is 29160000, while the sum is 55.

The spelling of 663955540543 in words is "six hundred sixty-three billion, nine hundred fifty-five million, five hundred forty thousand, five hundred forty-three".