2100131021 has 4 divisors (see below), whose sum is σ = 2101047612. Its totient is φ = 2099214432.

The previous prime is 2100131003. The next prime is 2100131029. The reversal of 2100131021 is 1201310012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1636202500 + 463928521 = 40450^2 + 21539^2 .

It is a cyclic number.

It is not a de Polignac number, because 2100131021 - 2¹⁴ = 2100114637 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2100130993 and 2100131011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2100131029) 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 3 ways as a sum of consecutive naturals, for example, 454850 + ... + 459443.

It is an arithmetic number, because the mean of its divisors is an integer number (525261903).

Almost surely, 2^2100131021 is an apocalyptic number.

It is an amenable number.

2100131021 is a deficient number, since it is larger than the sum of its proper divisors (916591).

2100131021 is an equidigital number, since it uses as much as digits as its factorization.

2100131021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 916590.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 2100131021 is about 45827.1864835711. The cubic root of 2100131021 is about 1280.6057966182.

Adding to 2100131021 its reverse (1201310012), we get a palindrome (3301441033).

The spelling of 2100131021 in words is "two billion, one hundred million, one hundred thirty-one thousand, twenty-one".