636661663425543 has 8 divisors (see below), whose sum is σ = 970151106172288. Its totient is φ = 363806664814584.

The previous prime is 636661663425503. The next prime is 636661663425553. The reversal of 636661663425543 is 345524366166636.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 636661663425543 - 2²² = 636661659231239 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 (636661663425503) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15158611033921 + ... + 15158611033962.

It is an arithmetic number, because the mean of its divisors is an integer number (121268888271536).

Almost surely, 2^{636661663425543} is an apocalyptic number.

636661663425543 is a deficient number, since it is larger than the sum of its proper divisors (333489442746745).

636661663425543 is a wasteful number, since it uses less digits than its factorization.

636661663425543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30317222067893.

The product of its digits is 1007769600, while the sum is 66.

The spelling of 636661663425543 in words is "six hundred thirty-six trillion, six hundred sixty-one billion, six hundred sixty-three million, four hundred twenty-five thousand, five hundred forty-three".