2122121021 has 4 divisors (see below), whose sum is σ = 2127466812. Its totient is φ = 2116775232.

The previous prime is 2122121003. The next prime is 2122121041. The reversal of 2122121021 is 1201212212.

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 1925980996 + 196140025 = 43886^2 + 14005^2 .

It is a cyclic number.

It is not a de Polignac number, because 2122121021 - 2³⁰ = 1048379197 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2122120987 and 2122121005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2122121041) 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, 2672300 + ... + 2673093.

It is an arithmetic number, because the mean of its divisors is an integer number (531866703).

Almost surely, 2^2122121021 is an apocalyptic number.

It is an amenable number.

2122121021 is a deficient number, since it is larger than the sum of its proper divisors (5345791).

2122121021 is an equidigital number, since it uses as much as digits as its factorization.

2122121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5345790.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 2122121021 is about 46066.4847910061. The cubic root of 2122121021 is about 1285.0599316979.

Adding to 2122121021 its reverse (1201212212), we get a palindrome (3323333233).

The spelling of 2122121021 in words is "two billion, one hundred twenty-two million, one hundred twenty-one thousand, twenty-one".