121221012217 has 2 divisors, whose sum is σ = 121221012218. Its totient is φ = 121221012216.

The previous prime is 121221012197. The next prime is 121221012233. The reversal of 121221012217 is 712210122121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 81341321616 + 39879690601 = 285204^2 + 199699^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121221012217 is a prime.

It is not a weakly prime, because it can be changed into another prime (121221012317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60610506108 + 60610506109.

It is an arithmetic number, because the mean of its divisors is an integer number (60610506109).

Almost surely, 2^121221012217 is an apocalyptic number.

It is an amenable number.

121221012217 is a deficient number, since it is larger than the sum of its proper divisors (1).

121221012217 is an equidigital number, since it uses as much as digits as its factorization.

121221012217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 224, while the sum is 22.

Adding to 121221012217 its reverse (712210122121), we get a palindrome (833431134338).

The spelling of 121221012217 in words is "one hundred twenty-one billion, two hundred twenty-one million, twelve thousand, two hundred seventeen".