2101220121 has 64 divisors (see below), whose sum is σ = 3863494656. Its totient is φ = 980294400.

The previous prime is 2101220087. The next prime is 2101220167. The reversal of 2101220121 is 1210221012.

It is not a de Polignac number, because 2101220121 - 2⁶ = 2101220057 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2101220097 and 2101220106.

It is not an unprimeable number, because it can be changed into a prime (2101220171) 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 63 ways as a sum of consecutive naturals, for example, 101656 + ... + 120566.

It is an arithmetic number, because the mean of its divisors is an integer number (60367104).

Almost surely, 2^2101220121 is an apocalyptic number.

2101220121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2101220121 is a deficient number, since it is larger than the sum of its proper divisors (1762274535).

2101220121 is a wasteful number, since it uses less digits than its factorization.

2101220121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18982.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 2101220121 is about 45839.0676279525. The cubic root of 2101220121 is about 1280.8271267378.

Adding to 2101220121 its reverse (1210221012), we get a palindrome (3311441133).

It can be divided in two parts, 2101 and 220121, that added together give a palindrome (222222).

The spelling of 2101220121 in words is "two billion, one hundred one million, two hundred twenty thousand, one hundred twenty-one".