100111121261 has 2 divisors, whose sum is σ = 100111121262.
Its totient is φ = 100111121260.
The previous prime is 100111121233. The next prime is 100111121317. The reversal of 100111121261 is 162121111001.
Adding to 100111121261 its reverse (162121111001), we get a palindrome (262232232262).
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 50818684900 + 49292436361 = 225430^2 + 222019^2
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-100111121261 is a prime.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (100111121861) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (23) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50055560630 + 50055560631.
It is an arithmetic number, because the mean of its divisors is an integer number (50055560631).
Almost surely, 2100111121261 is an apocalyptic number.
It is an amenable number.
100111121261 is a deficient number, since it is larger than the sum of its proper divisors (1).
100111121261 is an equidigital number, since it uses as much as digits as its factorization.
100111121261 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 24, while the sum is 17.
The spelling of 100111121261 in words is "one hundred billion, one hundred eleven million, one hundred twenty-one thousand, two hundred sixty-one".