2100121321 has 4 divisors (see below), whose sum is σ = 2100212992. Its totient is φ = 2100029652.

The previous prime is 2100121307. The next prime is 2100121337. The reversal of 2100121321 is 1231210012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 2100121321 - 2¹⁵ = 2100088553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2100121021) 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, 21640 + ... + 68326.

It is an arithmetic number, because the mean of its divisors is an integer number (525053248).

Almost surely, 2^2100121321 is an apocalyptic number.

It is an amenable number.

2100121321 is a deficient number, since it is larger than the sum of its proper divisors (91671).

2100121321 is an equidigital number, since it uses as much as digits as its factorization.

2100121321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91670.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 2100121321 is about 45827.0806510736. The cubic root of 2100121321 is about 1280.6038250118.

Adding to 2100121321 its reverse (1231210012), we get a palindrome (3331331333).

The spelling of 2100121321 in words is "two billion, one hundred million, one hundred twenty-one thousand, three hundred twenty-one".