2121222021021 has 12 divisors (see below), whose sum is σ = 3064006769980. Its totient is φ = 1414139057280.

The previous prime is 2121222021011. The next prime is 2121222021029. The reversal of 2121222021021 is 1201202221212.

It is a happy number.

2121222021021 is a `hidden beast` number, since 2 + 1 + 212 + 220 + 210 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1010706504921 + 1110515516100 = 1005339^2 + 1053810^2 .

It is not a de Polignac number, because 2121222021021 - 2¹³ = 2121222012829 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2121222020985 and 2121222021003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121222021029) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 958485 + ... + 2271813.

Almost surely, 2^{2121222021021} is an apocalyptic number.

It is an amenable number.

2121222021021 is a deficient number, since it is larger than the sum of its proper divisors (942784748959).

2121222021021 is a wasteful number, since it uses less digits than its factorization.

2121222021021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1492796 (or 1492793 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 2121222021021 its reverse (1201202221212), we get a palindrome (3322424242233).

The spelling of 2121222021021 in words is "two trillion, one hundred twenty-one billion, two hundred twenty-two million, twenty-one thousand, twenty-one".