21001221221041 has 2 divisors, whose sum is σ = 21001221221042. Its totient is φ = 21001221221040.

The previous prime is 21001221221033. The next prime is 21001221221147. The reversal of 21001221221041 is 14012212210012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15562512154225 + 5438709066816 = 3944935^2 + 2332104^2 .

It is a cyclic number.

It is not a de Polignac number, because 21001221221041 - 2³ = 21001221221033 is a prime.

It is a super-6 number, since 6×21001221221041⁶ (a number of 81 digits) contains 666666 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (21001221201041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500610610520 + 10500610610521.

It is an arithmetic number, because the mean of its divisors is an integer number (10500610610521).

Almost surely, 2^{21001221221041} is an apocalyptic number.

It is an amenable number.

21001221221041 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001221221041 is an equidigital number, since it uses as much as digits as its factorization.

21001221221041 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21001221221041 its reverse (14012212210012), we get a palindrome (35013433431053).

The spelling of 21001221221041 in words is "twenty-one trillion, one billion, two hundred twenty-one million, two hundred twenty-one thousand, forty-one".