661101101166 has 64 divisors (see below), whose sum is σ = 1449349770240. Its totient is φ = 199369820160.

The previous prime is 661101101161. The next prime is 661101101191.

661101101166 is nontrivially palindromic in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661101101161) 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 31 ways as a sum of consecutive naturals, for example, 26756130 + ... + 26780826.

It is an arithmetic number, because the mean of its divisors is an integer number (22646090160).

Almost surely, 2^661101101166 is an apocalyptic number.

661101101166 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

661101101166 is an abundant number, since it is smaller than the sum of its proper divisors (788248669074).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661101101166 is a wasteful number, since it uses less digits than its factorization.

661101101166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26649.

The product of its (nonzero) digits is 1296, while the sum is 30.

It can be divided in two parts, 661101 and 101166, that added together give a palindrome (762267).

The spelling of 661101101166 in words is "six hundred sixty-one billion, one hundred one million, one hundred one thousand, one hundred sixty-six".