111661102020 has 144 divisors (see below), whose sum is σ = 341660531520. Its totient is φ = 27233376768.

The previous prime is 111661101953. The next prime is 111661102027. The reversal of 111661102020 is 20201166111.

It is not an unprimeable number, because it can be changed into a prime (111661102027) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1054747 + ... + 1155773.

It is an arithmetic number, because the mean of its divisors is an integer number (2372642580).

Almost surely, 2^111661102020 is an apocalyptic number.

111661102020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 111661102020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (170830265760).

111661102020 is an abundant number, since it is smaller than the sum of its proper divisors (229999429500).

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

111661102020 is a wasteful number, since it uses less digits than its factorization.

111661102020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101174 (or 101159 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 21.

Adding to 111661102020 its reverse (20201166111), we get a palindrome (131862268131).

The spelling of 111661102020 in words is "one hundred eleven billion, six hundred sixty-one million, one hundred two thousand, twenty".