2221212220021 has 2 divisors, whose sum is σ = 2221212220022. Its totient is φ = 2221212220020.

The previous prime is 2221212220009. The next prime is 2221212220049. The reversal of 2221212220021 is 1200222121222.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2145094168996 + 76118051025 = 1464614^2 + 275895^2 .

It is a cyclic number.

It is not a de Polignac number, because 2221212220021 - 2¹⁹ = 2221211695733 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2221212220121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1110606110010 + 1110606110011.

It is an arithmetic number, because the mean of its divisors is an integer number (1110606110011).

Almost surely, 2^{2221212220021} is an apocalyptic number.

It is an amenable number.

2221212220021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2221212220021 is an equidigital number, since it uses as much as digits as its factorization.

2221212220021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 2221212220021 its reverse (1200222121222), we get a palindrome (3421434341243).

The spelling of 2221212220021 in words is "two trillion, two hundred twenty-one billion, two hundred twelve million, two hundred twenty thousand, twenty-one".