2121120021 has 16 divisors (see below), whose sum is σ = 2842716800. Its totient is φ = 1406818368.

The previous prime is 2121119993. The next prime is 2121120031. The reversal of 2121120021 is 1200211212.

It is not a de Polignac number, because 2121120021 - 2⁵ = 2121119989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2121119979 and 2121120006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121120031) 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 15 ways as a sum of consecutive naturals, for example, 687360 + ... + 690438.

It is an arithmetic number, because the mean of its divisors is an integer number (177669800).

Almost surely, 2^2121120021 is an apocalyptic number.

It is an amenable number.

2121120021 is a deficient number, since it is larger than the sum of its proper divisors (721596779).

2121120021 is a wasteful number, since it uses less digits than its factorization.

2121120021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4188.

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

The square root of 2121120021 is about 46055.6187777344. The cubic root of 2121120021 is about 1284.8578465690.

Adding to 2121120021 its reverse (1200211212), we get a palindrome (3321331233).

The spelling of 2121120021 in words is "two billion, one hundred twenty-one million, one hundred twenty thousand, twenty-one".