2221020212121 has 6 divisors (see below), whose sum is σ = 3208140306410. Its totient is φ = 1480680141408.

The previous prime is 2221020212119. The next prime is 2221020212123. The reversal of 2221020212121 is 1212120201222.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (2221020212119) and next prime (2221020212123).

It can be written as a sum of positive squares in only one way, i.e., 1188634160025 + 1032386052096 = 1090245^2 + 1016064^2 .

It is not a de Polignac number, because 2221020212121 - 2¹ = 2221020212119 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2221020212094 and 2221020212103.

It is not an unprimeable number, because it can be changed into a prime (2221020212123) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 123390011776 + ... + 123390011793.

Almost surely, 2^{2221020212121} is an apocalyptic number.

It is an amenable number.

2221020212121 is a deficient number, since it is larger than the sum of its proper divisors (987120094289).

2221020212121 is a wasteful number, since it uses less digits than its factorization.

2221020212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246780023575 (or 246780023572 counting only the distinct ones).

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

Adding to 2221020212121 its reverse (1212120201222), we get a palindrome (3433140413343).

The spelling of 2221020212121 in words is "two trillion, two hundred twenty-one billion, twenty million, two hundred twelve thousand, one hundred twenty-one".