17012011221221 has 4 divisors (see below), whose sum is σ = 17017568888844. Its totient is φ = 17006453553600.

The previous prime is 17012011221203. The next prime is 17012011221263. The reversal of 17012011221221 is 12212211021071.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14390558793121 + 2621452428100 = 3793489^2 + 1619090^2 .

It is a cyclic number.

It is not a de Polignac number, because 17012011221221 - 2²⁶ = 17011944112357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (17012011229221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2778829220 + ... + 2778835341.

It is an arithmetic number, because the mean of its divisors is an integer number (4254392222211).

Almost surely, 2^{17012011221221} is an apocalyptic number.

It is an amenable number.

17012011221221 is a deficient number, since it is larger than the sum of its proper divisors (5557667623).

17012011221221 is an equidigital number, since it uses as much as digits as its factorization.

17012011221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5557667622.

The product of its (nonzero) digits is 224, while the sum is 23.

Adding to 17012011221221 its reverse (12212211021071), we get a palindrome (29224222242292).

The spelling of 17012011221221 in words is "seventeen trillion, twelve billion, eleven million, two hundred twenty-one thousand, two hundred twenty-one".