21221122012061 has 2 divisors, whose sum is σ = 21221122012062. Its totient is φ = 21221122012060.

The previous prime is 21221122011989. The next prime is 21221122012117. The reversal of 21221122012061 is 16021022112212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20503553767225 + 717568244836 = 4528085^2 + 847094^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221122012061 - 2³⁰ = 21220048270237 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21229122012061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610561006030 + 10610561006031.

It is an arithmetic number, because the mean of its divisors is an integer number (10610561006031).

Almost surely, 2^{21221122012061} is an apocalyptic number.

It is an amenable number.

21221122012061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221122012061 is an equidigital number, since it uses as much as digits as its factorization.

21221122012061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 23.

Adding to 21221122012061 its reverse (16021022112212), we get a palindrome (37242144124273).

The spelling of 21221122012061 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred twenty-two million, twelve thousand, sixty-one".