100544666561 has 4 divisors (see below), whose sum is σ = 100545504192. Its totient is φ = 100543828932.

The previous prime is 100544666557. The next prime is 100544666591. The reversal of 100544666561 is 165666445001.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 100544666561 - 2² = 100544666557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (100544666501) 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, 201005 + ... + 491418.

It is an arithmetic number, because the mean of its divisors is an integer number (25136376048).

Almost surely, 2^100544666561 is an apocalyptic number.

It is an amenable number.

100544666561 is a deficient number, since it is larger than the sum of its proper divisors (837631).

100544666561 is an equidigital number, since it uses as much as digits as its factorization.

100544666561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 837630.

The product of its (nonzero) digits is 518400, while the sum is 44.

The spelling of 100544666561 in words is "one hundred billion, five hundred forty-four million, six hundred sixty-six thousand, five hundred sixty-one".