661803281113 has 16 divisors (see below), whose sum is σ = 737327344320. Its totient is φ = 589798085184.

The previous prime is 661803281071. The next prime is 661803281119. The reversal of 661803281113 is 311182308166.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661803281113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661803281119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9451570 + ... + 9521332.

It is an arithmetic number, because the mean of its divisors is an integer number (46082959020).

Almost surely, 2^661803281113 is an apocalyptic number.

It is an amenable number.

661803281113 is a deficient number, since it is larger than the sum of its proper divisors (75524063207).

661803281113 is a wasteful number, since it uses less digits than its factorization.

661803281113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94968.

The product of its (nonzero) digits is 41472, while the sum is 40.

Adding to 661803281113 its reverse (311182308166), we get a palindrome (972985589279).

The spelling of 661803281113 in words is "six hundred sixty-one billion, eight hundred three million, two hundred eighty-one thousand, one hundred thirteen".