2100220121 has 4 divisors (see below), whose sum is σ = 2151445044. Its totient is φ = 2048995200.

The previous prime is 2100220099. The next prime is 2100220139. The reversal of 2100220121 is 1210220012.

It is a happy number.

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 225330121 + 1874890000 = 15011^2 + 43300^2 .

It is a cyclic number.

It is not a de Polignac number, because 2100220121 - 2¹⁴ = 2100203737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2100222121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25612400 + ... + 25612481.

It is an arithmetic number, because the mean of its divisors is an integer number (537861261).

Almost surely, 2^2100220121 is an apocalyptic number.

It is an amenable number.

2100220121 is a deficient number, since it is larger than the sum of its proper divisors (51224923).

2100220121 is an equidigital number, since it uses as much as digits as its factorization.

2100220121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51224922.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 2100220121 is about 45828.1586036358. The cubic root of 2100220121 is about 1280.6239066570.

Adding to 2100220121 its reverse (1210220012), we get a palindrome (3310440133).

The spelling of 2100220121 in words is "two billion, one hundred million, two hundred twenty thousand, one hundred twenty-one".