2100121101 has 80 divisors (see below), whose sum is σ = 3536055600. Its totient is φ = 1233211392.

The previous prime is 2100121081. The next prime is 2100121103. The reversal of 2100121101 is 1011210012.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 340402500 + 1759718601 = 18450^2 + 41949^2 .

It is not a de Polignac number, because 2100121101 - 2¹³ = 2100112909 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2100121103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 2961735 + ... + 2962443.

It is an arithmetic number, because the mean of its divisors is an integer number (44200695).

Almost surely, 2^2100121101 is an apocalyptic number.

It is an amenable number.

2100121101 is a deficient number, since it is larger than the sum of its proper divisors (1435934499).

2100121101 is a wasteful number, since it uses less digits than its factorization.

2100121101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 860 (or 851 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

The square root of 2100121101 is about 45827.0782507460. The cubic root of 2100121101 is about 1280.6037802949.

Adding to 2100121101 its reverse (1011210012), we get a palindrome (3111331113).

It can be divided in two parts, 2100 and 121101, that added together give a square (123201 = 351²).

The spelling of 2100121101 in words is "two billion, one hundred million, one hundred twenty-one thousand, one hundred one".